0001127537-21-000018 | 10-Q | XBRL Viewer

Balance Sheet Components (Tables)

3 Months Ended

Mar. 31, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The Company’s cash and cash equivalents consist of the following (in thousands):


	March 31,		December 31,
	2021		2020
Cash	$	206,743	$	221,028
Cash equivalents:
Money market funds	1,540		10,533
Commercial paper	1,000		—
Total cash and cash equivalents	$	209,283	$	231,561

Schedule of Inventory

Inventory consists of the following (in thousands):


	March 31,		December 31,
	2021		2020
Raw materials	$	3,043	$	3,342
Work in process	313		227
Finished goods	8,560		7,172
Total inventory	$	11,916	$	10,741

Schedule of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following (in thousands):


	March 31,		December 31,
	2021		2020
Prepaid expenses	$	754	$	381
Prepaid insurance	1,486		2,131
VAT receivable	224		339
Other current assets	547		377
Total prepaid expenses and other current assets	$	3,011	$	3,228

Schedule of Property and Equipment, Net

Property and equipment, net consist of the following (in thousands):


	March 31,		December 31,
	2021		2020
Machinery and equipment	$	1,511	$	1,447
Computer equipment and software	1,084		1,062
Furniture and fixtures	228		229
Leasehold improvements	172		57
Construction in progress	660		452
Total	3,655		3,247
Less: accumulated depreciation	(1,856)		(1,773)
Property and equipment, net	$	1,799	$	1,474

Schedule Intangible Assets

Intangible assets consist of the following (in thousands):


	March 31, 2021
	Gross Carrying Value		Accumulated Amortization		Net Carrying Value
Developed technology	$	1,658	$	(1,326)	$	332
Trademarks	191		(153)		38
Total intangible assets	$	1,849	$	(1,479)	$	370


	December 31, 2020
	Gross Carrying Value		Accumulated Amortization		Net Carrying Value
Developed technology	$	1,658	$	(1,299)	$	359
Trademarks	191		(150)		41
Total intangible assets	$	1,849	$	(1,449)	$	400

Schedule of Future Amortization Expense

Future amortization expense is as follows as of March 31, 2021 (in thousands):



2021 (remaining nine months)	$	93
2022	123
2023	123
2024	31
Total amortization expense	$	370

Schedule of Accrued Liabilities

Accrued liabilities consist of the following (in thousands):


	March 31,		December 31,
	2021		2020
Accrued employee bonuses and commissions	$	1,989	$	2,374
Accrued vacation	1,941		1,810
Other accrued personnel related expenses	2,382		1,368
Accrued professional fees	1,781		1,313
Sales taxes, franchise tax and VAT	379		521
Liability for early exercise of stock options	537		629
Inventory in transit	70		57
Other	677		579
Total accrued liabilities	$	9,756	$	8,651

Long Term Debt and Convertible Notes - 2020 Notes Narrative (Details) - USD ($)		1 Months Ended
	Oct. 05, 2020	Apr. 30, 2020	Mar. 31, 2021
Debt Instrument [Line Items]
Embedded derivative liability		$ 3,900,000
Accrued interest			$ 1,777,000
2020 Notes Agreement
Debt Instrument [Line Items]
Aggregate outstanding principal amount of debt	$ 33,000,000.0
Accrued interest	800,000
Convertible Debt \| 2020 Notes Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 66,000,000.0
Remaining borrowing capacity			$ 33,000,000.0
Accrued interest	$ 800,000
Convertible Debt \| 2020 Notes Agreement \| Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate		2.00%
Convertible Debt \| 2020 Notes Agreement \| Common Stock
Debt Instrument [Line Items]
Conversion price per share (in dollars per share)	$ 13.20
Shares issued upon conversion of debt (in shares)	2,561,484
Convertible Debt \| 2020 Notes Agreement \| Debt Instrument, Convertible, Conversion Feature, Scenario Two
Debt Instrument [Line Items]
Conversion price per share (in dollars per share)		$ 13.20
Convertible Debt \| 2020 Notes Agreement, Tranche One
Debt Instrument [Line Items]
Proceeds from convertible debt		$ 33,000,000.0
Convertible Debt \| 2020 Notes Agreement Over Allotment Option
Debt Instrument [Line Items]
Maximum draw amount		5,000,000.0
Convertible Debt \| 2020 Notes Agreement, Tranche Two \| Maximum
Debt Instrument [Line Items]
Remaining borrowing capacity		$ 33,000,000.0

Long Term Debt And Convertible Notes - Oxford Finance Loan Narrative (Details) - USD ($)			1 Months Ended	3 Months Ended		12 Months Ended
	Oct. 05, 2020	Feb. 20, 2020	Aug. 31, 2014	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2014
Debt Instrument [Line Items]
Interest expense on deferred financing and debt issuance costs, less than				$ 39,000	$ 211,000
Medium-term Notes \| Oxford Finance Loan
Debt Instrument [Line Items]
Debt instrument, face amount including accordion feature			$ 20,000,000.0
Proceeds from issuance of debt						$ 15,000,000.0
Stated interest rate			8.96%
Debt term			5 years
Interest payments term			36 months
Principal and interest payments term			24 months
Final payment, percentage of loan amount due			8.50%
Contingent fee amount, maximum			$ 2,500,000
Payments of debt fees	$ 1,900,000
Repayments on term loan obligations		$ 17,300,000
Extinguishment of debt		15,000,000.0
Final payment on loan		1,300,000
Fee amount		900,000
Accrued interest		100,000
Loss on extinguishment of debt		$ 400,000
Interest expense on deferred financing and debt issuance costs, less than					$ 100,000
Interest expense				$ 400,000

Summary of Significant Accounting Policies (Policies)	3 Months Ended
Summary of Significant Accounting Policies (Policies)	Mar. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The Company’s unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”).
Principles of Consolidation	Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of unaudited interim condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited interim condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Significant estimates and assumptions include reserves and write-downs related to inventories, the recoverability of long term assets, valuation of equity instruments and equity-linked instruments, valuation of common stock, stock-based compensation, valuation of the derivative liability, intangible assets, goodwill, debt and related features, deferred tax assets and related valuation allowances and impact of contingencies.
Fair Value of Financial Instruments	Fair Value of Financial Instruments The carrying amounts of the Company’s financial instruments consisting of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. The derivative liabilities were carried at fair value based on unobservable market inputs. Based on the borrowing rates currently available to the Company for debt with similar terms and consideration of default and credit risk, the carrying value of the term loan approximates their fair value. The fair value of marketable debt securities is estimated using Level 2 inputs based on their quoted market values (Note 4).
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of risk consist principally of cash, cash equivalents and accounts receivable. The Company maintains its cash and cash equivalents balances with established financial institutions and, at times, such balances with any one financial institution may be in excess of the Federal Deposit Insurance Corporation (“FDIC”) insured limits.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs, consisting of legal, accounting and other fees and costs relating to the Company’s IPO, are capitalized and recorded on the balance sheet. During the year ended December 31, 2020, the Company wrote off deferred offering costs of $3.0 million as, in May 2020, the Company withdrew its registration statement that was filed with the SEC in February 2020. After the registration statement was withdrawn in May 2020, an additional $1.8 million in deferred offering costs were incurred related to the Company’s October 2020 IPO. In connection with the IPO, all deferred offering costs incurred after May 2020 were recorded as reduction of the gross proceeds from the IPO in the additional paid-in capital on the accompanying balance sheet as of December 31, 2020. There were no deferred offering costs capitalized as of March 31, 2021.
Foreign Currency Translation and Transaction Gains and Losses	Foreign Currency Translation and Transaction Gains and Losses The functional currencies of the Company’s wholly owned subsidiaries in the Cayman Islands and the Netherlands are the U.S. dollar. The functional currencies of the Company’s wholly owned subsidiaries in Switzerland, Germany, Australia, the United Kingdom, France and Hong Kong are the Swiss franc. The functional currency of the Company’s subsidiary in Italy is the Euro. Accordingly, asset and liability accounts of Switzerland, Germany, Australia, the United Kingdom, Italy and Hong Kong operations are translated into U.S. dollars using the current exchange rate in effect at the balance sheet date and equity accounts are translated into U.S. dollars using historical rates. The revenues and expenses are translated using the average exchange rates in effect during the period, and gains and losses from foreign currency translation adjustments are included as a component of accumulated other comprehensive income in the condensed consolidated balance sheet. Foreign currency translation adjustments are recorded in other comprehensive income (loss) in the condensed consolidated statements of operations and comprehensive loss and was $(0.3) million and $0.3 million during the three months ended March 31, 2021 and 2020, respectively. Foreign currency transaction gains and losses are included in other income (expense), net in the condensed consolidated statements of operations and comprehensive loss
Net Loss per Share Attributable to Common Stockholders	Net Loss per Share Attributable to Common Stockholders Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common stock outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, convertible preferred stock, stock options, common stock subject to repurchase related to early exercise of stock options, and convertible preferred stock warrants are considered to be potentially dilutive securities. Basic and diluted net loss attributable to common stockholders per share is presented in conformity with the two-class method required for participating securities as the convertible preferred stock is considered a participating security because it participates in dividends with common stock. The Company also considers the shares issued upon the early exercise of stock options subject to repurchase to be participating securities, because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. The holders of all series of convertible preferred stock and the holders of the shares issued upon early exercise of stock options subject to repurchase do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Because the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods.
Recently Adopted Accounting Pronouncements and Recent Accounting Pronouncements Not Yet Adopted	Recently Adopted Accounting Pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This ASU is effective for public business entities for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. The Company adopted ASU 2019-12 as of January 1, 2021 and the adoption did not have a material impact on the Company’s unaudited interim condensed consolidated financial statements. Recent Accounting Pronouncements Not Yet Adopted In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) (“ASU 2020-04”). The amendments in ASU 2020-04 provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in ASU 2020-04 are effective for all entities as of March 12, 2020 through December 31, 2022. An entity may elect to apply the amendments for contract modifications by Topic or Industry Subtopic as of any date from the beginning an interim period that includes or is subsequent to March 12, 2020, or prospectively from the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic, the amendments must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. The Company may elect to apply ASU 2020-04 as its contracts referenced in London Interbank Offered Rate (“LIBOR”) are impacted by reference rate reform. The Company is currently evaluating the impact of the adoption of this ASU on the Company’s consolidated financial statements. In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity's Own Equity (Subtopic 815-40)—Accounting For Convertible Instruments and Contracts in an Entity's Own Equity (“ASU 2020-06”). ASU 2020-06 simplifies accounting for convertible instruments by removing major separation models required under current GAAP. Consequently, more convertible debt instruments will be reported as a single liability instrument with no separate accounting for embedded conversion features. ASU 2020-06 removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception, which will permit more equity contracts to qualify for it. ASU 2020-06 also simplifies the diluted net income per share calculation in certain areas. This ASU is effective for the Company for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years, with early adoption permitted for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. The Company is currently evaluating the impact of the adoption of this principle on the Company’s consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses. This new guidance will require financial instruments to be measured at amortized cost, and trade accounts receivable to be presented at the net amount expected to be collected. The new model requires an entity to estimate credit losses based on historical information, current information and reasonable and supportable forecasts, including estimates of prepayments. In November 2019, the FASB issued ASU 2019-10, according to which, the new standard is effective for public business entities that meet the definition of an SEC filer, excluding entities eligible to be smaller reporting companies (“SRC”) as defined by the SEC, for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. For all other entities, including the Company, the new standard is effective for fiscal years beginning after December 15, 2022, and interim periods within that fiscal year. Early adoption is permitted. The Company is currently evaluating the impact of the new standard on the Company’s consolidated financial statements.
Assets and Liabilities Measured at Fair Value	Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis – Financial assets and liabilities held by the Company measured at fair value on a recurring basis include money market funds, marketable securities, convertible preferred stock warrant liability and derivative liabilities. Assets and Liabilities Measured and Recorded at Fair Value on a Nonrecurring Basis – The Company determines the fair value of long-lived assets held and used, such as intangible assets, by reference to independent appraisals, quoted market prices (e.g. an offer to purchase) and other factors. An impairment charge is recorded when the carrying value of the asset exceeds its fair value. As noted above, there have been no impairment charges recorded to date. Based on the borrowing rates currently available to the Company for debt with similar terms and consideration of default and credit risk, the carrying value of the term loan approximates the fair value and is classified as a Level 2 liability. Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability.

Leases, Lease Commitments and Contingencies - Other Supplemental Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Cash paid for amounts included in the measurement of lease liabilities included in cash flows used in operating activities	$ 541	$ 228

Balance Sheet Components - Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Prepaid expenses	$ 754	$ 381
Prepaid insurance	1,486	2,131
VAT receivable	224	339
Other current assets	547	377
Total prepaid expenses and other current assets	$ 3,011	$ 3,228

Convertible Preferred Stock	3 Months Ended
Convertible Preferred Stock	Mar. 31, 2021
Temporary Equity Disclosure [Abstract]
Convertible Preferred Stock	Convertible Preferred Stock Under the Company’s Amended and Restated Certificate of Incorporation, the Company is not authorized to issue any shares of convertible preferred stock. Upon the closing of the IPO in October 2020, all outstanding shares of the convertible preferred stock converted into 17,797,026 shares of common stock and the related carrying value was reclassified to common stock and additional paid-in capital. There was no issued and outstanding convertible preferred stock as of March 31, 2021 and December 31, 2020.

Balance Sheet Components - Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash	$ 206,743	$ 221,028
Cash equivalents:
Money market funds	1,540	10,533
Commercial paper	1,000	0
Total cash and cash equivalents	$ 209,283	$ 231,561	$ 16,241

Leases, Lease Commitments and Contingencies

3 Months Ended

Mar. 31, 2021

Leases [Abstract]

Leases, Lease Commitments and Contingencies

The Company has a lease for its headquarters location in Redwood City, California. In October 2019, the Company renewed its lease for the headquarters location in Redwood City, California for an additional five years commencing in August 2020 and expiring in July 2025. The monthly base rent during the renewed term is $0.1 million and is subject to an annual increase of 3.5%. The Company is responsible for its share of real estate taxes, common area maintenance and management fees. The Company is eligible to receive a tenant improvement allowance of $0.2 million on commencement of the renewal term in August 2020.

During 2013, the Company entered into a five-year lease for office facilities in Switzerland. The Company had an option to extend the lease through January 2022, which was not exercised by the Company. Per the lease terms, in the event the option to extend is not exercised, the lease remains in force and can be terminated with 12-months’ notice.

In April 2020, the Company executed a sublease for another office facility in Redwood City, California for a three-year term commencing on June 1, 2020. The lease agreement provides for early termination if the Company or Sublandlord elects to terminate the lease by providing the other party at least 180 days prior written notice. The early termination may only occur on or after the expiration of the 18th full calendar month of the sublease term. The lease term for this lease is 18 months as the possible exercise of the early termination option by the Sublandlord is not within the Company’s control. The monthly base rent during the term is less than $0.1 million and is subject to an annual increase of 3.5%. The Company is responsible for its share of real estate taxes, common area maintenance and management fees.

In September 2020, the Company amended a sublease agreement entered in April 2020, to include additional facility space in Redwood City, California for a four-year term. The amendment was accounted as a separate sublease agreement. The sublease agreement contained a rent free period through February 14, 2021, after which rent is

approximately $0.1 million per month and is subject to an annual increase of 3.5%. The Company is responsible for its share of real estate taxes, common area maintenance and management fees. The Company is eligible to receive a tenant improvement allowance of $0.6 million to fund facility enhancements. The sublease agreement can be extended for an additional twelve month period, at the Company’s option. For accounting purposes, the lease term is 4 years as it is not reasonably certain that the Company will exercise the renewal option. The amendment also changed the lease term of sublease agreement entered in April 2020, which was extended until May 31, 2024, but left the early termination clause unchanged.

The Company has leases on two vehicle leases with terms ranging from 2 to 4 years.

Operating lease cost consists of the following (in thousands):


	Three Months Ended March 31,
	2021		2020
Operating lease cost	$	728	$	380
Short-term lease cost	3		3
Variable lease cost	147		60
Total lease cost	$	878	$	443

The following table summarizes a maturity analysis of the Company’s lease liabilities showing the aggregate lease payments as of March 31, 2021 (in thousands):


2021 (remaining nine months)	$	2,224
2022	2,069
2023	2,795
2024	2,589
2025	1,007
Total minimum lease payments	10,684
Less: Amount of lease payments representing interest	1,210
Present value of future minimum lease payments	$	9,474
Less: Current lease liabilities	1,774
Long-term lease liabilities	$	7,700

The following table summarizes additional information related to the Company’s operating leases (in thousands, except weighted average data):


	March 31, 2021		December 31, 2020
Right of use asset	$	8,404	$	8,976
Weighted average remaining lease term (years)	3.91		4.13
Weighted average discount rate (percent)	6.1		6.1

The following table summarizes other supplemental information related to the Company’s operating leases (in thousands):


	Three Months Ended March 31,
	2021		2020
Cash paid for amounts included in the measurement of lease liabilities included in cash flows used in operating activities	$	541	$	228

Contingencies

From time to time, the Company may be a party to various litigation claims in the normal course of business. Legal fees and other costs associated with such actions are expensed as incurred. The Company assesses, in conjunction with legal counsel, the need to record a liability for litigation and contingencies. Accrual estimates are recorded when and if it is determinable that such a liability for litigation and contingencies are both probable and reasonably estimable.

In December 2018, a former distributor outside the United States filed suit alleging the Company’s subsidiary, PulmonX International Sàrl, conducted unfair competitive practices and violated the exclusive distribution rights as a result of the subsidiary’s termination of its distribution agreement. The complaint seeks pecuniary and non-pecuniary damages. The Company is in the initial stages of evaluating this matter and does not believe the impact of any such matter will be material to the Company’s results of operation or financial position.

Segment Information - Revenue by Geographic Area (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 9,244	$ 8,618
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	4,289	4,489
Europe, Middle-East and Africa (“EMEA”)
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	4,044	3,457
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	911	633
Other International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 0	$ 39

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 50
-Paragraph 32
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
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-Paragraph 4
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8736-108599

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e9054-108599

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130545-203045

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Formation and Business of the Company (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
	Oct. 05, 2020	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Subsidiary, Sale of Stock [Line Items]
Accrued interest		$ 1,777
Common stock, authorized (in shares)	200,000,000	200,000,000		200,000,000
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001		$ 0.001
Convertible preferred stock, shares authorized (in shares)	10,000,000
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001		$ 0.001
Accumulated deficit		$ 254,779		$ 242,734
Cash used in operating activities		9,672	$ 9,849
Cash, cash equivalents and marketable securities		$ 221,600
2020 Notes Agreement
Subsidiary, Sale of Stock [Line Items]
Aggregate outstanding principal amount of debt	$ 33,000
Accrued interest	800
2020 Notes Agreement \| Convertible Debt
Subsidiary, Sale of Stock [Line Items]
Accrued interest	$ 800
2020 Notes Agreement \| Convertible Debt \| Common Stock
Subsidiary, Sale of Stock [Line Items]
Shares issued upon conversion of debt (in shares)	2,561,484
Conversion price per share (in dollars per share)	$ 13.20
Common Stock
Subsidiary, Sale of Stock [Line Items]
Conversion of convertible securities (in shares)	17,797,026
IPO
Subsidiary, Sale of Stock [Line Items]
Shares issued in transaction (in shares)	11,500,000
Share price (in dollars per share)	$ 19.00
Proceeds from initial public offering	$ 218,500
Proceeds from initial public offering, net of issuance costs	$ 201,400
Over-Allotment Option
Subsidiary, Sale of Stock [Line Items]
Shares issued in transaction (in shares)	1,500,000

Long Term Debt and Convertible Notes - Credit Agreement and Paycheck Protection Program Narrative (Details) - Line of Credit - COVID-19 Credit Agreement - Pulmonx International Sarl SFr in Millions	1 Months Ended			3 Months Ended
	May 31, 2020 USD ($)	May 31, 2020 CHF (SFr)	Apr. 30, 2020 USD ($)	Mar. 31, 2021 USD ($)	Apr. 30, 2020 CHF (SFr)
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 500,000		SFr 0.5
Proceeds from line of credit	$ 500,000	SFr 0.5
Debt term			60 months
Repayments on credit agreement				$ 0

Balance Sheet Components

3 Months Ended

Mar. 31, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Balance Sheet Components

Cash and Cash Equivalents

The Company’s cash and cash equivalents consist of the following (in thousands):


	March 31,		December 31,
	2021		2020
Cash	$	206,743	$	221,028
Cash equivalents:
Money market funds	1,540		10,533
Commercial paper	1,000		—
Total cash and cash equivalents	$	209,283	$	231,561

Inventory

Inventory consists of the following (in thousands):


	March 31,		December 31,
	2021		2020
Raw materials	$	3,043	$	3,342
Work in process	313		227
Finished goods	8,560		7,172
Total inventory	$	11,916	$	10,741

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following (in thousands):


	March 31,		December 31,
	2021		2020
Prepaid expenses	$	754	$	381
Prepaid insurance	1,486		2,131
VAT receivable	224		339
Other current assets	547		377
Total prepaid expenses and other current assets	$	3,011	$	3,228

Property and Equipment, Net

Property and equipment, net consist of the following (in thousands):


	March 31,		December 31,
	2021		2020
Machinery and equipment	$	1,511	$	1,447
Computer equipment and software	1,084		1,062
Furniture and fixtures	228		229
Leasehold improvements	172		57
Construction in progress	660		452
Total	3,655		3,247
Less: accumulated depreciation	(1,856)		(1,773)
Property and equipment, net	$	1,799	$	1,474

Depreciation expense for the three months ended March 31, 2021 and March 31, 2020 was $0.1 million and $0.1 million, respectively.

Goodwill

Goodwill was $2.3 million as of March 31, 2021 and December 31, 2020 arising from the Company’s acquisition of Emphasys Medical, Inc, in March 2009. No goodwill impairment losses have been recognized since the acquisition. There were no acquisitions or dispositions of goodwill in three months ended March 31, 2021 and 2020. The Company assesses goodwill for impairment annually, or more frequently, when events or changes in circumstances indicate there may be impairment. Through March 31, 2021, there have been no events or changes in circumstances

that indicated that the carrying value of goodwill may not be recoverable. As a result, no impairment charge was recorded during the three months ended March 31, 2021.

Intangible Assets

Intangible assets consist of the following (in thousands):


	March 31, 2021
	Gross Carrying Value		Accumulated Amortization		Net Carrying Value
Developed technology	$	1,658	$	(1,326)	$	332
Trademarks	191		(153)		38
Total intangible assets	$	1,849	$	(1,479)	$	370


	December 31, 2020
	Gross Carrying Value		Accumulated Amortization		Net Carrying Value
Developed technology	$	1,658	$	(1,299)	$	359
Trademarks	191		(150)		41
Total intangible assets	$	1,849	$	(1,449)	$	400

Amortization expense relating to the intangibles totaled less than $0.1 million during each of the three months ended March 31, 2021 and March 31, 2020, respectively.

Future amortization expense is as follows as of March 31, 2021 (in thousands):



2021 (remaining nine months)	$	93
2022	123
2023	123
2024	31
Total amortization expense	$	370

Accrued Liabilities

Accrued liabilities consist of the following (in thousands):


	March 31,		December 31,
	2021		2020
Accrued employee bonuses and commissions	$	1,989	$	2,374
Accrued vacation	1,941		1,810
Other accrued personnel related expenses	2,382		1,368
Accrued professional fees	1,781		1,313
Sales taxes, franchise tax and VAT	379		521
Liability for early exercise of stock options	537		629
Inventory in transit	70		57
Other	677		579
Total accrued liabilities	$	9,756	$	8,651

Fair Value Measurements - Fair Value of Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets:
Short-term marketable securities	$ 12,282
U.S. Treasury bonds
Assets:
Short-term marketable securities	507
U.S. Government agency bonds
Assets:
Short-term marketable securities	3,008
Corporate bonds
Assets:
Short-term marketable securities	773
Recurring Basis
Assets:
Cash equivalents	2,540	$ 10,533
Short-term marketable securities	12,282
Total financial assets	14,822	10,533
Recurring Basis \| U.S. Treasury bonds
Assets:
Short-term marketable securities	507
Recurring Basis \| U.S. Government agency bonds
Assets:
Short-term marketable securities	3,008
Recurring Basis \| Corporate bonds
Assets:
Short-term marketable securities	773
Recurring Basis \| Commercial paper
Assets:
Short-term marketable securities	7,994
Level 1 \| Recurring Basis
Assets:
Cash equivalents	1,540	10,533
Short-term marketable securities	507
Total financial assets	2,047	10,533
Level 1 \| Recurring Basis \| U.S. Treasury bonds
Assets:
Short-term marketable securities	507
Level 1 \| Recurring Basis \| U.S. Government agency bonds
Assets:
Short-term marketable securities	0
Level 1 \| Recurring Basis \| Corporate bonds
Assets:
Short-term marketable securities	0
Level 1 \| Recurring Basis \| Commercial paper
Assets:
Short-term marketable securities	0
Level 2 \| Recurring Basis
Assets:
Cash equivalents	1,000	0
Short-term marketable securities	11,775
Total financial assets	12,775	0
Level 2 \| Recurring Basis \| U.S. Treasury bonds
Assets:
Short-term marketable securities	0
Level 2 \| Recurring Basis \| U.S. Government agency bonds
Assets:
Short-term marketable securities	3,008
Level 2 \| Recurring Basis \| Corporate bonds
Assets:
Short-term marketable securities	773
Level 2 \| Recurring Basis \| Commercial paper
Assets:
Short-term marketable securities	7,994
Level 3 \| Recurring Basis
Assets:
Cash equivalents	0	0
Short-term marketable securities	0
Total financial assets	0	0
Level 3 \| Recurring Basis \| U.S. Treasury bonds
Assets:
Short-term marketable securities	0
Level 3 \| Recurring Basis \| U.S. Government agency bonds
Assets:
Short-term marketable securities	0
Level 3 \| Recurring Basis \| Corporate bonds
Assets:
Short-term marketable securities	0
Level 3 \| Recurring Basis \| Commercial paper
Assets:
Short-term marketable securities	0
Money market funds \| Recurring Basis
Assets:
Cash equivalents	1,540	10,533
Money market funds \| Level 1 \| Recurring Basis
Assets:
Cash equivalents	1,540	10,533
Money market funds \| Level 2 \| Recurring Basis
Assets:
Cash equivalents	0	0
Money market funds \| Level 3 \| Recurring Basis
Assets:
Cash equivalents	0	$ 0
Commercial paper \| Recurring Basis
Assets:
Cash equivalents	1,000
Commercial paper \| Level 1 \| Recurring Basis
Assets:
Cash equivalents	0
Commercial paper \| Level 2 \| Recurring Basis
Assets:
Cash equivalents	1,000
Commercial paper \| Level 3 \| Recurring Basis
Assets:
Cash equivalents	$ 0

Fair Value Measurements - Change in Fair Value of Liabilities (Details) - Success Fee Derivative Liability $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Derivative Liability
Beginning fair value	$ 1,165
Change in fair value	(330)
Ending fair value	$ 835

Net Loss per Share Attributable to Common Stockholders (Tables)

3 Months Ended

Mar. 31, 2021

Earnings Per Share [Abstract]

Schedule of Basic and Diluted Net Loss per Share

The following table sets forth the computation of basic and diluted net loss per share attributable to common stockholders which excludes shares which are legally outstanding, but subject to repurchase by the Company (in thousands, except share and per share amounts):


	Three Months Ended March 31,
	2021		2020
Numerator
Net loss attributable to common stockholders	$	(12,045)	$	(7,163)
Denominator
Weighted-average common stock outstanding	35,702,465		2,104,721
Less: weighted-average common shares subject to repurchase	(331,705)		(198,006)
Weighted-average common shares used to compute basic and diluted net loss per share	35,370,760		1,906,715
Net loss per share attributable to common stockholders, basic and diluted	$	(0.34)	$	(3.76)

Schedule of Potentially Dilutive Securities Outstanding

The following potentially dilutive securities outstanding have been excluded from the computation of diluted weighted average shares outstanding because such securities have an antidilutive impact due to the Company’s net loss, in common stock equivalent shares:


	As of March 31,
	2021	2020
Convertible preferred stock	—	17,797,026
Options to purchase common stock	2,759,165	3,302,838
Unvested early exercised common stock options	303,899	198,012
Shares committed under ESPP	99,144	—
Total	3,162,208	21,297,876

Net Loss per Share Attributable to Common Stockholders - Excluded Potentially Dilutive Securities Outstanding (Details) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	3,162,208	21,297,876
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	0	17,797,026
Options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	2,759,165	3,302,838
Unvested early exercised common stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	303,899	198,012
Common stock available for ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive securities excluded from computation of diluted weighted average shares outstanding (in shares)	99,144	0

Fair Value Measurements

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Fair Value Measurements

Assets and liabilities recorded at fair value in the consolidated financial statements are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Hierarchical levels which are directly related to the amount of subjectivity associated with the inputs to the valuation of these assets or liabilities are as follows:

Level 1 – Inputs are unadjusted quoted prices in active markets for identical assets or liabilities that the Company has the ability to access as of the measurement date.

Level 2 – Inputs are observable, unadjusted quoted prices in active markets for similar assets or liabilities, unadjusted quoted prices for identical or similar assets or liabilities in markets that are not active or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the related assets or liabilities;

Level 3 – Unobservable inputs for the asset or liability only used when there is little, if any, market activity for the asset or liability at the measurement date. This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value.

Assets and Liabilities Measured and Recorded at Fair Value on a Recurring Basis – Financial assets and liabilities held by the Company measured at fair value on a recurring basis include money market funds, marketable securities, convertible preferred stock warrant liability and derivative liabilities.

Assets and Liabilities Measured and Recorded at Fair Value on a Nonrecurring Basis – The Company determines the fair value of long-lived assets held and used, such as intangible assets, by reference to independent appraisals, quoted market prices (e.g. an offer to purchase) and other factors. An impairment charge is recorded when the carrying value of the asset exceeds its fair value. As noted above, there have been no impairment charges recorded to date. Based on the borrowing rates currently available to the Company for debt with similar terms and consideration of default and credit risk, the carrying value of the term loan approximates the fair value and is classified as a Level 2 liability.

Assets and liabilities measured at fair value are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgments and consider factors specific to the asset or liability.

The following tables summarizes the types of assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


	March 31, 2021
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	1,540	$	—	$	—	$	1,540
Commercial paper	—		1,000		—		1,000
Cash equivalents	1,540		1,000		—		2,540
U.S. Treasury bonds	507		—		—		507
U.S. Government agency bonds	—		3,008		—		3,008
Corporate bonds	—		773		—		773
Commercial paper	—		7,994		—		7,994
Marketable securities	507		11,775		—		12,282
Total financial assets	$	2,047	$	12,775	$	—	$	14,822

There were no liabilities measured at fair value on a recurring and non-recurring basis as of March 31, 2021.


	December 31, 2020
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	10,533	$	—	$	—	$	10,533
Cash equivalents	10,533		—		—		10,533
Total financial assets	$	10,533	$	—	$	—	$	10,533

There were no liabilities measured at fair value on a recurring and non-recurring basis as of December 31, 2020.

The following table summarizes the cost, unrealized gains and losses and fair value of marketable securities (in thousands):


	March 31, 2021
	Amortized Cost		Unrealized Losses		Unrealized Gains		Fair Value
U.S. Treasury bonds	$	507	$	—	$	—	$	507
U.S. Government agency bonds	3,009		(1)		—		3,008
Corporate bonds	774		(1)		—		773
Commercial paper	7,995		(1)		—		7,994
Marketable securities	$	12,285	$	(3)	$	—	$	12,282
Amounts recognized on the consolidated balance sheet
Cash equivalents							$	1,000
Short-term marketable securities							9,784
Long-term marketable securities							2,498
Marketable securities							$	13,282

The Company did not have any marketable securities as of December 31, 2020.

Accrued interest on marketable securities of less than $0.1 million is included in prepaid expenses and other current assets on the condensed consolidated balance sheet.

The Company valued a Success Fee derivative liability based on the Success Fee amount of $1.9 million and the probability and estimated timing of a liquidity event. Changes in the estimated probability may result in an increase or decrease in the fair value of the derivative liability. On October 5, 2020, the Success Fee derivative liability was settled upon the Company paying $1.9 million pursuant to the Success Fee Agreement to Oxford Finance LLC.

The change in fair value of the Success Fee derivative liability is summarized below (in thousands):


	Success Fee Derivative Liability
Beginning fair value, January 1, 2020	$	1,165
Change in fair value	(330)
Ending fair value, March 31, 2020	$	835

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2021

Fair Value Disclosures [Abstract]

Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following tables summarizes the types of assets and liabilities measured at fair value on a recurring basis by level within the fair value hierarchy (in thousands):


	March 31, 2021
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	1,540	$	—	$	—	$	1,540
Commercial paper	—		1,000		—		1,000
Cash equivalents	1,540		1,000		—		2,540
U.S. Treasury bonds	507		—		—		507
U.S. Government agency bonds	—		3,008		—		3,008
Corporate bonds	—		773		—		773
Commercial paper	—		7,994		—		7,994
Marketable securities	507		11,775		—		12,282
Total financial assets	$	2,047	$	12,775	$	—	$	14,822

There were no liabilities measured at fair value on a recurring and non-recurring basis as of March 31, 2021.


	December 31, 2020
	Level 1		Level 2		Level 3		Total
Assets:
Money market funds	$	10,533	$	—	$	—	$	10,533
Cash equivalents	10,533		—		—		10,533
Total financial assets	$	10,533	$	—	$	—	$	10,533

Schedule of Cost, Unrealized Gains and Losses and Fair Value of Marketable Securities

The following table summarizes the cost, unrealized gains and losses and fair value of marketable securities (in thousands):


	March 31, 2021
	Amortized Cost		Unrealized Losses		Unrealized Gains		Fair Value
U.S. Treasury bonds	$	507	$	—	$	—	$	507
U.S. Government agency bonds	3,009		(1)		—		3,008
Corporate bonds	774		(1)		—		773
Commercial paper	7,995		(1)		—		7,994
Marketable securities	$	12,285	$	(3)	$	—	$	12,282
Amounts recognized on the consolidated balance sheet
Cash equivalents							$	1,000
Short-term marketable securities							9,784
Long-term marketable securities							2,498
Marketable securities							$	13,282

Schedule of Fair Value of Liabilities

The change in fair value of the Success Fee derivative liability is summarized below (in thousands):


	Success Fee Derivative Liability
Beginning fair value, January 1, 2020	$	1,165
Change in fair value	(330)
Ending fair value, March 31, 2020	$	835

Segment Information - Narrative (Details) - segment	3 Months Ended
Segment Information - Narrative (Details) - segment	Mar. 31, 2021	Mar. 31, 2020
Concentration Risk [Line Items]
Number of reportable segments	1
Number of operating segments	1
GERMANY \| Revenue from Contract with Customer Benchmark \| Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%	17.00%
FRANCE \| Revenue from Contract with Customer Benchmark \| Geographic Concentration Risk
Concentration Risk [Line Items]
Concentration risk, percentage	11.00%	9.00%

Stockholders' Equity - Narrative (Details)	3 Months Ended		12 Months Ended
Stockholders' Equity - Narrative (Details)	Mar. 31, 2021 USD ($) vote $ / shares shares	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($) shares	Oct. 05, 2020 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, authorized (in shares) \| shares	200,000,000		200,000,000	200,000,000
Dividends declared	$ 0
Number of votes for each share of common stock held \| vote	1
Weighted average exercise price (in dollars per share) \| $ / shares	$ 5.05
Options outstanding, aggregate intrinsic value	$ 112,500,000
Options exercisable, aggregate intrinsic value	112,500,000
Options vested and expenses to vest, intrinsic value	$ 53,300,000
Repurchase of early exercised common stock options (in shares) \| shares	12,945
Common stock, shares repurchased, less than (in shares)	$ 100,000
Aggregate exercise price of shares subject to repurchase	500,000		$ 600,000
Unrecognized compensation costs	14,100,000
Cost Of Goods And Services Sold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation capitalized into inventory	100,000	$ 0
Inventory, Net
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation capitalized into inventory	$ 300,000	$ 0
Options to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	4 years
Shares subject to repurchase (in shares) \| shares	303,899		355,677
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Non-option unrecognized compensation costs	$ 800,000
Weighted-average period for recognition of compensation costs	2 months 12 days
Stock Options And Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted-average period for recognition of compensation costs	2 years 2 months 4 days

Balance Sheet Components - Property and Equipment, Net (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 3,655	$ 3,247
Less: accumulated depreciation	(1,856)	(1,773)
Property and equipment, net	1,799	1,474
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	1,511	1,447
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	1,084	1,062
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	228	229
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	172	57
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment, gross	$ 660	$ 452

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 209,283	$ 231,561
Restricted cash	231	231
Short-term marketable securities	9,784	0
Accounts receivable, net	5,119	4,228
Inventory	11,916	10,741
Prepaid expenses and other current assets	3,011	3,228
Total current assets	239,344	249,989
Property and equipment, net	1,799	1,474
Goodwill	2,333	2,333
Intangible assets, net	370	400
Right of use assets	8,404	8,976
Long-term marketable securities	2,498	0
Other long-term assets	522	536
Total assets	255,270	263,708
Current liabilities
Accounts payable	1,826	1,472
Accrued liabilities	9,756	8,651
Income taxes payable	120	94
Deferred revenue	75	71
Term loan, current	472	0
Current lease liabilities	1,774	2,238
Total current liabilities	14,023	12,526
Deferred tax liability	71	62
Long-term lease liabilities	7,700	7,618
Credit agreement	532	564
Term loan	16,329	16,804
Total liabilities	38,655	37,574
Commitments and contingencies (Note 8)
Stockholders’ equity
Preferred stock, $0.001 par value, 10,000,000 shares authorized; no shares issued and outstanding as of March 31, 2021 and December 31, 2020	0	0
Common stock, $0.001 par value, 200,000,000 shares authorized as of March 31, 2021 and December 31, 2020; 35,803,664 shares issued and outstanding as of March 31, 2021 and 35,693,753 shares issued and outstanding as December 31, 2020	36	36
Additional paid-in capital	469,948	467,147
Accumulated other comprehensive income	1,410	1,685
Accumulated deficit	(254,779)	(242,734)
Total stockholders’ equity	216,615	226,134
Total liabilities, preferred stock and stockholders’ equity	$ 255,270	$ 263,708

Balance Sheet Components - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Depreciation expense	$ 100,000	$ 100,000
Goodwill	2,333,000		$ 2,333,000
Goodwill, accumulated impairment loss	0
Goodwill acquired	0	0
Goodwill disposed of	0	0
Goodwill, impairment loss	0
Amortization expense related to intangibles, less than	$ 100,000	$ 100,000

Fair Value Measurements - Narrative (Details) - USD ($)	Oct. 05, 2020	Mar. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Marketable securities		$ 13,282,000	$ 0
Accrued interest on marketable securities, less than		100,000
Oxford Finance Loan \| Medium-term Notes
Derivative [Line Items]
Payments of debt fees	$ 1,900,000
Success fee derivative liability
Derivative [Line Items]
Success Fee amount		$ 1,900,000

Leases, Lease Commitments and Contingencies - Maturity Analysis of Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Lessee, Operating Lease, Liability, Payment, Due [Abstract]
2021 (remaining 3 months)	$ 2,224
2022	2,069
2023	2,795
2024	2,589
2025	1,007
Total minimum lease payments	10,684
Less: Amount of lease payments representing interest	1,210
Present value of future minimum lease payments	9,474
Less: Current lease liabilities	1,774	$ 2,238
Long-term lease liabilities	$ 7,700	$ 7,618

Warrants for Convertible Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	2 Months Ended		3 Months Ended
	Feb. 29, 2020	Feb. 28, 2020	Mar. 31, 2020	Mar. 31, 2021	Dec. 31, 2020
Warrants and Rights Note Disclosure [Abstract]
Issuance of convertible preferred stock (in shares)	213,876		213,876
Convertible securities, exercise price per share (in dollars per share)		$ 10.57
Proceeds from stock issued		$ 2,300	$ 2,260
Warrants expired, unexercised (in shares)		1,415
Warrants outstanding (in shares)				0	0

Segment Information

3 Months Ended

Mar. 31, 2021

Segment Reporting [Abstract]

Segment Information

The chief operating decision maker for the Company is the Chief Executive Officer. The Company’s Chief Executive Officer reviews financial information presented on a consolidated basis, accompanied by information about revenue by geographic region, for purposes of allocating resources and evaluating financial performance. The Company has one business activity and there are no segment managers who are held accountable for operations, operating results or plans for levels or components below the consolidated unit level. Accordingly, the Company has determined that it has a single reportable and operating segment structure. The Company’s Chief Executive Officer evaluates performance based primarily on revenue in the geographic locations in which the Company operates.

Revenue by geographic area is based on the billing address of the customer. The following table sets forth the Company’s revenue by geographic area (in thousands):


	Three Months Ended March 31,
	2021		2020
United States	4,289		4,489
Europe, Middle-East and Africa (“EMEA”)	$	4,044	$	3,457
Asia Pacific	911		633
Other International	—		39
Total	$	9,244	$	8,618

Revenue from Germany and France represented 12% and 11%, respectively of total revenue for the three months ended March 31, 2021. Revenue from Germany and France represented 17% and 9%, respectively of total revenue for the three months ended March 31, 2020.

Long-lived assets by geographic area are based on physical location of those assets. The following table sets forth the Company’s long-lived assets by geographic area (in thousands):


	March 31		December 31,
	2021		2020
United States	$	1,749	$	1,437
EMEA	43		29
Asia Pacific	7		8
Total	$	1,799	$	1,474

- Definition

The entire disclosure for reporting segments including data and tables. Reportable segments include those that meet any of the following quantitative thresholds a) it's reported revenue, including sales to external customers and intersegment sales or transfers is 10 percent or more of the combined revenue, internal and external, of all operating segments b) the absolute amount of its reported profit or loss is 10 percent or more of the greater, in absolute amount of 1) the combined reported profit of all operating segments that did not report a loss or 2) the combined reported loss of all operating segments that did report a loss c) its assets are 10 percent or more of the combined assets of all operating segments.

+ References

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+ Details

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019	17,583,150
Beginning balance at Dec. 31, 2019	$ 205,339
Convertible Preferred Stock
Issuance of convertible preferred stock (in shares)	213,876
Issuance of convertible preferred stock	$ 2,260
Ending balance (in shares) at Mar. 31, 2020	17,797,026
Ending balance at Mar. 31, 2020	$ 207,599
Beginning balance (in shares) at Dec. 31, 2019		2,100,203
Beginning balance at Dec. 31, 2019	(187,378)	$ 2	$ 21,750	$ 1,373	$ (210,503)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)		7,164
Issuance of common stock upon exercise of stock options	11		11
Change in shares subject to repurchase	2		2
Stock-based compensation expense	209		209
Currency translation adjustment	282			282
Change in unrealized losses on marketable securities	(5)			(5)
Net loss	(7,163)				(7,163)
Ending balance (in shares) at Mar. 31, 2020		2,107,367
Ending balance at Mar. 31, 2020	$ (194,042)	$ 2	21,972	1,650	(217,666)
Beginning balance (in shares) at Dec. 31, 2020	35,693,753	35,693,753
Beginning balance at Dec. 31, 2020	$ 226,134	$ 36	467,147	1,685	(242,734)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock upon exercise of stock options (in shares)	122,856	122,856
Issuance of common stock upon exercise of stock options	$ 273		273
Repurchase of early exercised common stock options (in shares)		(12,945)
Change in shares subject to repurchase	66		66
Stock-based compensation expense	2,462		2,462
Currency translation adjustment	(272)			(272)
Change in unrealized losses on marketable securities	(3)			(3)
Net loss	$ (12,045)				(12,045)
Ending balance (in shares) at Mar. 31, 2021	35,803,664	35,803,664
Ending balance at Mar. 31, 2021	$ 216,615	$ 36	$ 469,948	$ 1,410	$ (254,779)

Balance Sheet Components - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued employee bonuses and commissions	$ 1,989	$ 2,374
Accrued vacation	1,941	1,810
Other accrued personnel related expenses	2,382	1,368
Accrued professional fees	1,781	1,313
Sales taxes, franchise tax and VAT	379	521
Liability for early exercise of stock options	537	629
Inventory in transit	70	57
Other	677	579
Total accrued liabilities	$ 9,756	$ 8,651

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Stockholders’ equity
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, authorized (in shares)	10,000,000	10,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, issued (in shares)	35,803,664	35,693,753
Common stock, outstanding (in shares)	35,803,664	35,693,753
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	200,000,000	200,000,000

Cover Page - shares	3 Months Ended
Cover Page - shares	Mar. 31, 2021	Apr. 30, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-39562
Entity Registrant Name	PULMONX CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	77-0424412
Entity Address, Address Line One	700 Chesapeake Drive
Entity Address, City or Town	Redwood City
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94063
Country Region	1
City Area Code	650
Local Phone Number	364-0400
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	LUNG
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		36,247,816
Entity Central Index Key	0001127537
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Amendment Flag	false

Leases, Lease Commitments and Contingencies - Narrative (Details) $ in Millions	1 Months Ended			6 Months Ended
	Sep. 30, 2020 USD ($)	Aug. 31, 2020 USD ($)	Apr. 30, 2020 USD ($)	Jun. 30, 2014	Mar. 31, 2021 lease	Dec. 31, 2013
Lessee, Lease, Description [Line Items]
Lease renewal term		5 years
Monthly base rent		$ 0.1
Annual increase rate		3.50%
Tenant improvement allowance, receivable upon lease renewal		$ 0.2
Option to terminate, notice period				12 months
Sublease term	4 years		3 years
Sublease, option to terminate, notice period			180 days
Sublease, period for option to terminate			18 months
Sublease monthly rent	$ 0.1		$ 0.1
Sublease, expense, annual increase rate	3.50%		3.50%
Sublease, tenant improvement allowance, receivable upon lease renewal	$ 0.6
Sublease renewal term	12 months
Number of vehicle leases \| lease					2
Office Facilities
Lessee, Lease, Description [Line Items]
Lease term						5 years
Minimum \| Vehicles
Lessee, Lease, Description [Line Items]
Lease term					2 years
Maximum \| Vehicles
Lessee, Lease, Description [Line Items]
Lease term					4 years

Revenue Recognition	3 Months Ended
Revenue Recognition	Mar. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition The Company’s contract liabilities consist of deferred revenue for remaining performance obligations by the Company to the customer after delivery, which was $0.1 million and $0.1 million as of March 31, 2021 and December 31, 2020, respectively. The deferred revenue as of December 31, 2019 was $0.2 million, which was recognized as revenue during the year ended December 31, 2020. The deferred revenue as of December 31, 2020 was $0.1 million, which was recognized as revenue during the three months ended March 31, 2021. The Company disaggregates its revenue by major geographic region, which has been disclosed in Note 14, “Segment Information”.

- Definition

The entire disclosure of revenue from contract with customer to transfer good or service and to transfer nonfinancial asset. Includes, but is not limited to, disaggregation of revenue, credit loss recognized from contract with customer, judgment and change in judgment related to contract with customer, and asset recognized from cost incurred to obtain or fulfill contract with customer. Excludes insurance and lease contracts.

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+ Details

Summary of Significant Accounting Policies (Details) $ in Thousands		3 Months Ended
	Sep. 22, 2020	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)	Dec. 31, 2020 USD ($)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stock split ratio	0.1
Cash on deposit with foreign banks		$ 5,100		$ 5,600
Write-off of deferred offering costs		3,000
Deferred offering costs		1,800
Other comprehensive income (loss,) foreign currency translation adjustments		(272)	$ 282
Foreign currency transaction gains and (losses)		200	(500)
Maximum
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss,) foreign currency translation adjustments		$ (300)	$ 300

Segment Information - Long-Lived Assets by Geographical Area (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 1,799	$ 1,474
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	1,749	1,437
Europe, Middle-East and Africa (“EMEA”)
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	43	29
Asia Pacific
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 7	$ 8

Warrants for Convertible Preferred Stock	3 Months Ended
Warrants for Convertible Preferred Stock	Mar. 31, 2021
Warrants and Rights Note Disclosure [Abstract]
Warrants for Convertible Preferred Stock	Warrants for Convertible Preferred Stock In January and February 2020, warrants to purchase 213,876 shares of Series C-1 convertible preferred stock were exercised at an exercise price of $10.57 per share, yielding $2.3 million cash proceeds. Warrants to purchase 1,415 shares of Series C-1 convertible preferred stock warrants expired unexercised. As of March 31, 2021 and December 31, 2020, no Series C-1 convertible preferred stock warrants were outstanding.

Leases, Lease Commitments and Contingencies - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Leases [Abstract]
Operating lease cost	$ 728	$ 380
Short-term lease cost	3	3
Variable lease cost	147	60
Total lease cost	$ 878	$ 443

Stockholders' Equity - Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs)	3 Months Ended
	Mar. 31, 2021 $ / shares shares
Number of Shares Underlying Outstanding Restricted Stock
Unvested, beginning of period (in shares) \| shares	0
Granted (in shares) \| shares	6,300
Unvested, end of period (in shares) \| shares	6,300
Weighted Average Grant Date Fair Value
Unvested, beginning of period (in dollars per share) \| $ / shares	$ 0
Granted (in dollars per share) \| $ / shares	60.17
Unvested, end of period (in dollars per share) \| $ / shares	$ 60.17

Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2021

Equity [Abstract]

Schedule of Shares Reserved for Future Issuance

The Company has reserved shares of common stock for future issuances as follows:


	March 31	December 31,
	2021	2020
Common stock options issued and outstanding	2,759,165	2,923,403
Common stock available for future grants	4,604,812	3,233,794
Common stock available for ESPP	1,076,937	720,000
Total	8,440,914	6,877,197

Schedule of Summary of Stock Option Activity

A summary of stock option activity for the three months ended March 31, 2021 is set forth below:


	Outstanding Options
	Number of Shares	Weighted Average Exercise Price
Balance, January 1, 2021	2,923,403	$	4.72
Options granted	8,600	62.34
Options exercised	(122,856)	2.22
Options canceled	(49,982)	2.44
Balance, March 31, 2021	2,759,165	$	5.05

Schedule of Options Vested and Expected to Vest


	March 31, 2021
	Number of Shares	Weighted Average Exercise Price		Weighted Average Contractual Life (in Years)
Options vested	1,223,414	$	2.20	4.91
Options vested and expected to vest	2,759,165	$	5.05	7.30

Schedule of Activity with Respect to Restricted Stock Units

Activity with respect to restricted stock units was as follows:


	Number of Shares Underlying Outstanding Restricted Stock	Weighted Average Grant Date Fair Value
Unvested, January 1, 2021	—	$	—
Granted	6,300	$	60.17
Unvested, March 31, 2021	6,300	$	60.17

Schedule of Total Stock-Based Compensation

Stock-based compensation expense is reflected in the statements of operations and comprehensive loss as follows (in thousands):


	Three Months Ended March 31,
	2021		2020
Cost of goods sold	$	90	$	15
Research and development	318		15
Selling, general and administrative	1,860		179
Total	$	2,268	$	209

The above stock-based compensation expense related to the following equity-based awards (in thousands):


	Three Months Ended March 31,
	2021		2020
Stock options and restricted stock units	$	1,039	$	209
ESPP	1,229		—
Total	$	2,268	$	209

Stock-based compensation of $0.3 million and $0 was capitalized into inventory for the three months ended March 31, 2021 and 2020, respectively. Stock-based compensation capitalized in prior periods of $0.1 million and $0 was recognized as cost of sales in the three months ended March 31, 2021 and 2020, respectively.

- Definition

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

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+ Details

Net Loss per Share Attributable to Common Stockholders

3 Months Ended

Mar. 31, 2021

Earnings Per Share [Abstract]

Net Loss per Share Attributable to Common Stockholders


	Three Months Ended March 31,
	2021		2020
Numerator
Net loss attributable to common stockholders	$	(12,045)	$	(7,163)
Denominator
Weighted-average common stock outstanding	35,702,465		2,104,721
Less: weighted-average common shares subject to repurchase	(331,705)		(198,006)
Weighted-average common shares used to compute basic and diluted net loss per share	35,370,760		1,906,715
Net loss per share attributable to common stockholders, basic and diluted	$	(0.34)	$	(3.76)


	As of March 31,
	2021	2020
Convertible preferred stock	—	17,797,026
Options to purchase common stock	2,759,165	3,302,838
Unvested early exercised common stock options	303,899	198,012
Shares committed under ESPP	99,144	—
Total	3,162,208	21,297,876

Leases, Lease Commitments and Contingencies (Tables)

3 Months Ended

Mar. 31, 2021

Leases [Abstract]

Schedule of Operating Lease Cost and Additional Information

Operating lease cost consists of the following (in thousands):


	Three Months Ended March 31,
	2021		2020
Operating lease cost	$	728	$	380
Short-term lease cost	3		3
Variable lease cost	147		60
Total lease cost	$	878	$	443

The following table summarizes additional information related to the Company’s operating leases (in thousands, except weighted average data):


	March 31, 2021		December 31, 2020
Right of use asset	$	8,404	$	8,976
Weighted average remaining lease term (years)	3.91		4.13
Weighted average discount rate (percent)	6.1		6.1

The following table summarizes other supplemental information related to the Company’s operating leases (in thousands):


	Three Months Ended March 31,
	2021		2020
Cash paid for amounts included in the measurement of lease liabilities included in cash flows used in operating activities	$	541	$	228

Schedule of Maturity Analysis of Lease Liabilities

The following table summarizes a maturity analysis of the Company’s lease liabilities showing the aggregate lease payments as of March 31, 2021 (in thousands):


2021 (remaining nine months)	$	2,224
2022	2,069
2023	2,795
2024	2,589
2025	1,007
Total minimum lease payments	10,684
Less: Amount of lease payments representing interest	1,210
Present value of future minimum lease payments	$	9,474
Less: Current lease liabilities	1,774
Long-term lease liabilities	$	7,700

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Revenue	$ 9,244	$ 8,618
Cost of goods sold	2,633	2,968
Gross profit	6,611	5,650
Operating expenses
Research and development	3,034	1,565
Selling, general and administrative	15,604	10,189
Total operating expenses	18,638	11,754
Loss from operations	(12,027)	(6,104)
Interest income	105	74
Interest expense	(217)	(899)
Other income (expense), net	161	(147)
Net loss before tax	(11,978)	(7,076)
Income tax expense	67	87
Net loss	(12,045)	(7,163)
Other comprehensive income
Currency translation adjustment	(272)	282
Change in unrealized losses on marketable securities	(3)	(5)
Total other comprehensive income (loss)	(275)	277
Comprehensive loss	$ (12,320)	$ (6,886)
Net loss per share attributable common stockholders, basic	$ (0.34)	$ (3.76)
Net loss per share attributable to common stockholders, diluted	$ (0.34)	$ (3.76)
Weighted-average shares used in computing net loss per share attributable to common stockholder, basic and diluted (in shares)	35,370,760	1,906,715

Stockholders' Equity - Total Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 2,268	$ 209
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,229	0
Stock Options And Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,039	209
Cost of goods sold
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	90	15
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	318	15
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,860	$ 179

Convertible Preferred Stock (Details) - shares	Oct. 05, 2020	Mar. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Preferred stock, issued (in shares)		0	0
Preferred stock, outstanding (in shares)		0	0
Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, issued (in shares)		0	0
Preferred stock, outstanding (in shares)		0	0
Common Stock
Class of Stock [Line Items]
Conversion of convertible securities (in shares)	17,797,026

Formation and Business of the Company	3 Months Ended
Formation and Business of the Company	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Formation and Business of the Company	Formation and Business of the Company The Company Pulmonx Corporation (the “Company”) was incorporated in the state of California in December 1995 as Pulmonx and reincorporated in the state of Delaware in December 2013. The Company is a commercial-stage medical technology company that provides a minimally invasive treatment for patients with severe emphysema, a form of chronic obstructive pulmonary disease (COPD). The Company’s solution, which is comprised of the Zephyr Endobronchial Valve (Zephyr Valve), the Chartis Pulmonary Assessment System (Chartis System) and the StratX Lung Analysis Platform (StratX Platform), is designed to treat a broad pool of patients for whom medical management has reached its limits and either do not want or are ineligible for surgical approaches. The Company has subsidiaries in the Cayman Islands, Germany, Switzerland, Australia, the United Kingdom, the Netherlands, Italy, France and Hong Kong. Initial Public Offering On September 30, 2020, the Company’s registration statement on Form S-1 (File No. 333-248635) relating to its initial public offering (“IPO”) of common stock became effective. The IPO closed on October 5, 2020 at which time the Company issued 11,500,000 shares of its common stock at a price of $19.00 per share, which included the issuance of shares in connection with the exercise by the underwriters of their option to purchase up to 1,500,000 additional shares. The Company received an aggregate of $218.5 million gross proceeds, before underwriting discounts, commissions and offering costs, and approximately $201.4 million in net proceeds after deducting underwriting discounts and commissions and offering costs. In addition, upon closing the IPO, all outstanding shares of the Company’s convertible preferred stock converted into 17,797,026 shares of common stock. Additionally, the $33.0 million aggregate outstanding principal amount and $0.8 million accrued interest of the 2020 Notes converted into 2,561,484 shares of common stock at a conversion price of $13.20 per share. In connection with the completion of its IPO, on October 5, 2020, the Company’s certificate of incorporation was amended and restated to provide for 200,000,000 authorized shares of common stock with a par value of $0.001 per share and 10,000,000 authorized shares of preferred stock with a par value of $0.001 per share. Liquidity and Going Concern The Company has incurred operating losses and negative cash flows from operations to date and has an accumulated deficit of $254.8 million as of March 31, 2021. During the three months ended March 31, 2021 and March 31, 2020, the Company used $9.7 million and $9.8 million of cash in its operating activities, respectively. As of March 31, 2021, the Company had cash, cash equivalents and marketable securities of $221.6 million. Historically, the Company’s activities have been financed through private placements of equity securities, debt and sale of common stock in the IPO. The Company’s condensed consolidated financial statements have been prepared on the basis of the Company continuing as a going concern for the next 12 months. Management believes that the Company’s existing cash, cash equivalents and marketable securities will allow the Company to continue its planned operations for at least the next 12 months from the date of the issuance of these unaudited interim condensed consolidated financial statements. Impact of the COVID-19 Pandemic The Company has been actively monitoring the novel coronavirus, or COVID-19, situation and its impact. In response to the pandemic, numerous state and local jurisdictions imposed travel bans, restrictions, social distancing requirements, quarantines, stay-at-home orders and other significant measures. In the markets in which we operate, elective, specialty and other procedures and appointments were suspended or canceled. The COVID-19 pandemic has significantly delayed and decreased the number of procedures performed using the Company’s products and otherwise adversely impacted sales and operations. The Company’s unaudited interim condensed consolidated financial statements reflect judgments and estimates that could change in the future as a result of the COVID-19 pandemic. The COVID-19 pandemic has adversely impacted the Company’s business, financial condition and results of operations by decreasing and delaying substantially all procedures performed using its products, and the Company expects the pandemic to continue to have an adverse impact on its business, financial condition and results of operations for the foreseeable future.

Long Term Debt and Convertible Notes - Contractual Maturities of Financing Obligations (Details) $ in Thousands	Mar. 31, 2021 USD ($)
Long-term Debt, Fiscal Year Maturity [Abstract]
2021 (remaining three months)	$ 544
2022	5,369
2023	6,078
2024	5,837
2025	1,480
Total	19,308
Less: unamortized debt discount	(198)
Less: interest	(1,777)
Outstanding loan amount	$ 17,333

Balance Sheet Components - Future Amortization Expense (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2021 (remaining three months)	$ 93
2022	123
2023	123
2024	31
Net Carrying Value	$ 370	$ 400

Leases, Lease Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Right of use asset	$ 8,404	$ 8,976
Weighted average remaining lease term (years)	3 years 10 months 28 days	4 years 1 month 17 days
Weighted average discount rate (percent)	6.10%	6.10%

Long Term Debt and Convertible Notes

3 Months Ended

Mar. 31, 2021

Debt Disclosure [Abstract]

Long Term Debt and Convertible Notes

Term Loan

Oxford Finance Loan

From August 2014 until February 2020, the Company was party to a Loan and Security Agreement with Oxford, which provided the ability to borrow up to $20.0 million in term loans (“Oxford Finance Loan”). In 2014, the Company borrowed $15.0 million. The term loan bore interest at 8.96% and had a five-year term. The first 36 months were interest only payments followed by 24 months of equal payments of principal and interest. A final payment of 8.50% of the term loan amount was due at maturity and was being accreted using the effective interest rate method. The term loan was collateralized by assets, including cash and cash equivalents, accounts receivable and property and equipment. The Oxford Finance Loan was subsequently amended in 2017 and 2018 to extend the interest only period and to extend the maturity date to July 1, 2020, and at the Company’s option, further extend the maturity date to May 1, 2021. In 2019, the Company elected to extend the maturity date to May 2021.

In connection with the original agreement in August 2014, the Company also entered into the Success Fee Agreement. In the event of a sale or other disposition by the Company of all or substantially all of its assets, a merger or consolidation, or an initial public offering (a “Liquidity Event”), before the termination of the agreement on August 28, 2021, the Company was required to pay up to $2.5 million (the “Success Fee”) to Oxford Finance LLC, the amount of which would be based on actual borrowings, up to $20.0 million. This agreement was identified as a freestanding derivative under ASC 815, Derivatives (“Success Fee”) and was remeasured to its fair value at the end of each reporting period and any change in fair value is recognized as change in other income (expense), net in the statements of operations and comprehensive loss (Note 4). On October 5, 2020, in connection with the IPO, the Company paid $1.9 million pursuant to the Success Fee Agreement to Oxford Finance LLC based on the $15.0 million borrowed.

On February 20, 2020, the Company repaid its entire obligation under the term loan agreement with Oxford Finance LLC amounting to $17.3 million, including outstanding loan amount of $15.0 million, final payment of $1.3 million, amendment fees of $0.9 million and accrued interest of $0.1 million. The repayment of the obligation under the term loan agreement with Oxford Finance LLC was accounted as extinguishment and the Company recorded a loss on extinguishment of $0.4 million included in interest expense in the condensed consolidated statements of operations and comprehensive loss.

During the three months ended March 31, 2020, the Company recorded interest expense related to deferred financing and debt issuance costs of Oxford Finance Loan of less than $0.1 million.

Interest expense on the term loan amounted to $0.4 million during the three months ended March 31, 2020.

CIBC Loan

On February 20, 2020, the Company executed a Loan and Security Agreement (the “CIBC Agreement”) with Canadian Imperial Bank of Commerce (“CIBC”) to raise up to $32.0 million in debt financing (“CIBC Loan”) consisting of $17.0 million advanced at the closing of the agreement (Tranche A), with the option to drawing up to an additional $8.0 million (Tranche B) on or before February 20, 2022. The term loan also provides for an additional financing tranche (Tranche C) of up to $7.0 million on or prior to February 20, 2022, which is conditioned upon achieving a trailing six-month revenue of at least $20.0 million as of the date of any Tranche C borrowing. The availability of Tranche B and Tranche C is further conditioned upon the joining of Pulmonx International Sàrl to the CIBC Agreement and the execution by Pulmonx International Sàrl of Swiss-law collateral documentation in favor of CIBC. The CIBC Loan originally had a five-year term maturing on February 20, 2025, which included 24 months of interest only payments followed by 36 months of equal payments of principal and interest. The interest only period can be extended to 36 months if the Company achieves three-month trailing revenue of at least $20.0 million as of February 20, 2022. The CIBC Loan bears interest at a floating rate equal to 1.0% above the Wall Street Journal Prime Rate at any time. The Tranche C loan will bear interest at a floating rate equal to 1.5% above the Wall Street

Journal Prime Rate at any time. The CIBC Loan is collateralized by substantially all of the Company’s assets, including cash and cash equivalents, accounts receivable, intellectual property and equipment. The Company may prepay the loan, subject to certain requirements. The CIBC Agreement includes customary restrictive covenants, financial covenants, events of default and other customary terms and conditions.

In April 2020, the Company entered into a First Amendment to CIBC Agreement that changed the maturity date to March 15, 2022, which shall be automatically extended to February 20, 2025 if the maturity of all outstanding convertible notes (see below) is extended to a date no earlier than May 21, 2025 or all convertible notes have been converted into convertible preferred stock of the Company. An amendment fee of $0.2 million was paid. The Tranche B drawing is conditioned to achieving a trailing six-month revenue of at least $15.0 million as of the date of any Tranche B borrowing. On the date of drawing Tranche B Loan or Tranche C Loan, the Company will pay a structuring fee in an amount equal to 1.0% of the amount of Tranche B Loan or Tranche C Loan. The amendment was accounted for as a debt modification and no gain or loss was recognized.

In December 2020, to address certain post-close covenants for which the Company was not in compliance, the Company entered into a Second Amendment to the CIBC Agreement that extended the compliance of such covenants to June 30, 2021.

In March 2021, the Company entered into a Third Amendment to CIBC Agreement which extended the maturity date from March 15, 2022 to February 20, 2025, and modified certain financial covenants. Per the amended terms, 36 equal payments of principal plus accrued interest will be due beginning March 31, 2022. The beginning of principal repayment can be extended to March 31, 2023 if the Company achieves three-month trailing revenue of at least $20.0 million as of February 20, 2022. In connection with the Third Amendment the Company paid fees to CIBC of less than $0.1 million which were recorded as a discount on the CIBC Loan and are being accreted over the life of the term loan using the effective interest method. The amendment was accounted for as a debt modification and no gain or loss was recognized.

As of March 31, 2021, the CIBC Loan had an annual effective interest rate of 4.78% per year.

The financial covenants in the CIBC Agreement require that, when the cash and cash equivalents of the Company is less than $100.0 million, the Company to have revenue for the trailing three-month period ending on the last day of each fiscal quarter of not less than 80.0% of the revenue for the trailing three-month period, as set forth in the annual projections delivered to the CIBC. Further, the Company is required to maintain unrestricted cash in an aggregate amount equal to or greater than the Adjusted EBITDA loss as defined in the CIBC Agreement for the four-month period ending on any date of determination. As of March 31, 2021, the Company was in compliance with all covenants contained in CIBC Agreement.

The CIBC Loan consists of the following (in thousands):


	March 31,		December 31,
	2021		2020
Term loan	$	17,000	$	17,000
Less: debt issuance costs	(199)		(196)
Term loan	$	16,801	$	16,804

The Company paid $0.4 million fees to the lender and third parties which is reflected as a discount on the CIBC Loan and is being accreted over the life of the term loan using the effective interest method.

During each three months ended March 31, 2021 and 2020, the Company recorded interest expense related to debt discount and debt issuance costs of CIBC Loan of less than $0.1 million, respectively.

Interest expense on the CIBC Loan amounted $0.2 million and $0.1 million during the three months ended March 31, 2021 and 2020, respectively.

Credit Agreement

In April 2020, Pulmonx International Sàrl, a wholly-owned subsidiary of the Company, entered into a COVID-19 Credit Agreement with UBS Switzerland AG to receive up to 0.5 million Swiss Francs ($0.5 million U.S. dollar equivalent) under Swiss Federal Government program to mitigate the economic impact of the spread of the coronavirus. In May 2020, Pulmonx International Sàrl received $0.5 million Swiss Francs ($0.5 million U.S. dollar equivalent) under the COVID-19 Credit Agreement. The COVID-19 Credit Agreement will bear no interest and is payable within 60 months after receipt of funds. As of March 31, 2021, Pulmonx International Sàrl did not make any repayment of credit agreement.

2020 Notes

In April 2020, the Company entered into a Note Purchase Agreement and Convertible Promissory Notes (collectively the “2020 Notes Agreement”) with certain investors (the “Lenders”) to issue convertible promissory notes (the “2020 Notes”) for a maximum aggregate amount of $66.0 million. In April 2020, the Company received $33.0 million in gross proceeds from issuance of the 2020 Notes. Upon meeting customary closing conditions, the Company can draw up to an additional $33.0 million, provided that any such draw be for no less than $5.0 million on or prior to April 17, 2022. All unpaid interest and principal will be due and payable upon request of the majority of Lenders (“Majority Holders”) on or after the earlier of April 17, 2022 or an event of default. The 2020 Notes accrue interest at a rate equal to 2.0% above the Wall Street Journal Prime Rate. The Company may prepay the 2020 Notes prior to April 17, 2022 only with the consent of the Majority Holders.

The 2020 Notes included embedded derivatives that are required to be bifurcated from the 2020 Notes and accounted for separately as a single, compound embedded derivative instrument under ASC 815, Derivatives (“2020 Notes derivative liability”). The Company determined that a share settled redemption in the case of a financing or an IPO as described in the 2020 Notes represented an embedded derivative that was not clearly and closely related to the debt host and had accounted for these settlement alternatives as separate embedded derivative liability. The fair value of the 2020 derivative liability of $3.9 million was recorded on the issuance date of the 2020 Notes resulting in a debt discount, which was reported as a direct deduction from the face amount of the 2020 Notes. The 2020 derivative liability was remeasured to its fair value at the end of each reporting period and any change in fair value is recognized in other income (expense), net in the statements of operations and comprehensive loss.

Upon the closing of the IPO in October 2020, the $33.0 million aggregate outstanding principal amount and $0.8 million accrued interest of the 2020 Notes converted into 2,561,484 shares of common stock pursuant to the Qualified IPO conversion at the $13.20 per share fixed price. The Company determined that the 2020 Notes derivative had no value upon the closing of the IPO, because value of the notes with and without such derivative was the same.

At March 31, 2021, the Company retained the ability to draw up to an additional $33.0 million under the 2020 Notes Agreement until the maturity date in April 2022. The Company’s obligations with respect to the 2020 Notes are unsecured and subordinated to its obligations with respect to the CIBC Loan. The 2020 Notes have customary events of default.

Contractual Maturities of Financing Obligations

As of March 31, 2021, the aggregate future payments under the CIBC Loan and Credit Agreement (including interest payments) are as follows (in thousands):


2021 (remaining nine months)	$	544
2022	5,369
2023	6,078
2024	5,837
2025	1,480
Total	19,308
Less: unamortized debt discount	(198)
Less: interest	(1,777)
Term loan and credit agreement	$	17,333

Summary of Significant Accounting Policies	3 Months Ended
Summary of Significant Accounting Policies	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation The Company’s unaudited interim condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“U.S. GAAP”). Any reference in these notes to applicable guidance is meant to refer to the authoritative United States generally accepted accounting principles as found in the Accounting Standards Codification (“ASC”) and Accounting Standards Updates (“ASU”) of the Financial Accounting Standards Board (“FASB”). Reverse Stock Split On September 22, 2020, the Company effected a 1-for-10 reverse stock split of the Company’s common stock and convertible preferred stock. The par value and authorized shares of common stock were not adjusted as a result of the reverse stock split. All issued and outstanding common stock, convertible preferred stock, stock options and per share amounts contained in the accompanying financial statements and notes to the financial statements have been retroactively adjusted to give effect to the reverse stock split for all periods presented. Principles of Consolidation The consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation. Unaudited Interim Financial Information The condensed consolidated balance sheet as of December 31, 2020 was derived from the Company’s audited financial statements, but does not include all disclosures required by GAAP. The accompanying unaudited condensed consolidated financial statements as of March 31, 2021 and for the three months ended March 31, 2021 and 2020, have been prepared by the Company, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”), for interim financial statements. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. However, the Company believes that the disclosures are adequate to make the information presented not misleading. Accordingly, these financial statements should be read in conjunction with the audited financial statements as of and for the year ended December 31, 2020 and notes thereto, included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020 filed with the SEC on March 15, 2021. In the opinion of management, all adjustments, consisting only of normal recurring adjustments necessary for a fair statement of the Company’s condensed consolidated financial position as of March 31, 2021 and condensed consolidated results of operations and cash flows for the three months ended March 31, 2021 and 2020 have been made. The results of operations for the three months ended March 31, 2021 are not necessarily indicative of the results of operations that may be expected for the year ending December 31, 2021. Use of Estimates The preparation of unaudited interim condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited interim condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting periods. Although these estimates are based on the Company’s knowledge of current events and actions it may undertake in the future, actual results may ultimately materially differ from these estimates and assumptions. Significant estimates and assumptions include reserves and write-downs related to inventories, the recoverability of long term assets, valuation of equity instruments and equity-linked instruments, valuation of common stock, stock-based compensation, valuation of the derivative liability, intangible assets, goodwill, debt and related features, deferred tax assets and related valuation allowances and impact of contingencies. Fair Value of Financial Instruments The carrying amounts of the Company’s financial instruments consisting of cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate fair value due to their relatively short maturities. The derivative liabilities were carried at fair value based on unobservable market inputs. Based on the borrowing rates currently available to the Company for debt with similar terms and consideration of default and credit risk, the carrying value of the term loan approximates their fair value. The fair value of marketable debt securities is estimated using Level 2 inputs based on their quoted market values (Note 4). Concentration of Credit Risk Financial instruments that potentially subject the Company to concentrations of risk consist principally of cash, cash equivalents and accounts receivable. The Company maintains its cash and cash equivalents balances with established financial institutions and, at times, such balances with any one financial institution may be in excess of the Federal Deposit Insurance Corporation (“FDIC”) insured limits. As of March 31, 2021 and December 31, 2020, the Company also had cash on deposit with foreign banks of approximately $5.1 million and $5.6 million, respectively, that was not federally insured. The Company earns revenue from the sale of its products to distributors and other customers such as hospitals. Sales of Zephyr Valves and delivery catheters accounted for most of the Company’s revenue for the three months ended March 31, 2021 and 2020. The Company’s accounts receivable are derived from revenue earned from distributors and customers. The Company performs ongoing credit evaluations of its customers’ and distributors’ financial condition and generally requires no collateral from its customers and distributors. At March 31, 2021 and December 31, 2020, no customer or distributor accounted for more than 10% of accounts receivable. During the three months ended March 31, 2021 and March 31, 2020, no customer or distributor accounted for more than 10% of revenue. The Company relies on single source suppliers for the components, sub-assemblies and materials for its products. These components, sub-assemblies and materials are critical and there are no or relatively few alternative sources of supply. The Company’s suppliers have generally met the Company’s demand for their products and services on a timely basis in the past. Deferred Offering Costs Deferred offering costs, consisting of legal, accounting and other fees and costs relating to the Company’s IPO, are capitalized and recorded on the balance sheet. During the year ended December 31, 2020, the Company wrote off deferred offering costs of $3.0 million as, in May 2020, the Company withdrew its registration statement that was filed with the SEC in February 2020. After the registration statement was withdrawn in May 2020, an additional $1.8 million in deferred offering costs were incurred related to the Company’s October 2020 IPO. In connection with the IPO, all deferred offering costs incurred after May 2020 were recorded as reduction of the gross proceeds from the IPO in the additional paid-in capital on the accompanying balance sheet as of December 31, 2020. There were no deferred offering costs capitalized as of March 31, 2021. Foreign Currency Translation and Transaction Gains and Losses The functional currencies of the Company’s wholly owned subsidiaries in the Cayman Islands and the Netherlands are the U.S. dollar. The functional currencies of the Company’s wholly owned subsidiaries in Switzerland, Germany, Australia, the United Kingdom, France and Hong Kong are the Swiss franc. The functional currency of the Company’s subsidiary in Italy is the Euro. Accordingly, asset and liability accounts of Switzerland, Germany, Australia, the United Kingdom, Italy and Hong Kong operations are translated into U.S. dollars using the current exchange rate in effect at the balance sheet date and equity accounts are translated into U.S. dollars using historical rates. The revenues and expenses are translated using the average exchange rates in effect during the period, and gains and losses from foreign currency translation adjustments are included as a component of accumulated other comprehensive income in the condensed consolidated balance sheet. Foreign currency translation adjustments are recorded in other comprehensive income (loss) in the condensed consolidated statements of operations and comprehensive loss and was $(0.3) million and $0.3 million during the three months ended March 31, 2021 and 2020, respectively. Foreign currency transaction gains and losses are included in other income (expense), net in the condensed consolidated statements of operations and comprehensive loss and was $0.2 million and $(0.5) million during the three months ended March 31, 2021 and 2020, respectively. Net Loss per Share Attributable to Common Stockholders Basic net loss per common share is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of common stock outstanding during the period, without consideration of potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common stock and potentially dilutive securities outstanding for the period. For purposes of the diluted net loss per share calculation, convertible preferred stock, stock options, common stock subject to repurchase related to early exercise of stock options, and convertible preferred stock warrants are considered to be potentially dilutive securities. Basic and diluted net loss attributable to common stockholders per share is presented in conformity with the two-class method required for participating securities as the convertible preferred stock is considered a participating security because it participates in dividends with common stock. The Company also considers the shares issued upon the early exercise of stock options subject to repurchase to be participating securities, because holders of such shares have non-forfeitable dividend rights in the event a dividend is paid on common stock. The holders of all series of convertible preferred stock and the holders of the shares issued upon early exercise of stock options subject to repurchase do not have a contractual obligation to share in the Company’s losses. As such, the net loss was attributed entirely to common stockholders. Because the Company has reported a net loss for all periods presented, diluted net loss per common share is the same as basic net loss per common share for those periods.

Income Taxes	3 Months Ended
Income Taxes	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The income tax expense for the three months ended March 31, 2021 and 2020 was determined based upon estimates of the Company’s effective income tax rates in various jurisdictions. The difference between the Company’s effective income tax rate and the U.S. federal statutory rate is primarily attributable to state income taxes, foreign income taxes, the effect of certain permanent differences, and full valuation allowance against net deferred tax assets. The income tax expense for the three months ended March 31, 2021 and 2020 relates primarily to state minimum income tax and income tax on the Company’s earnings in foreign jurisdictions. The Coronavirus Aid, Relief, and Economic Security (“CARES”) Act enacted in March 2020 did not provide an income tax benefit for the Company given its historical U.S. losses and a full valuation allowance against its net U.S. deferred tax assets.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Recent Accounting Pronouncements	3 Months Ended
Recent Accounting Pronouncements	Mar. 31, 2021
Accounting Policies [Abstract]
Recent Accounting Pronouncements	Recent Accounting Pronouncements Recently Adopted Accounting Pronouncements In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which is intended to simplify various aspects related to accounting for income taxes. ASU 2019-12 removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This ASU is effective for public business entities for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. The Company adopted ASU 2019-12 as of January 1, 2021 and the adoption did not have a material impact on the Company’s unaudited interim condensed consolidated financial statements. Recent Accounting Pronouncements Not Yet Adopted In March 2020, the FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848) (“ASU 2020-04”). The amendments in ASU 2020-04 provide optional expedients and exceptions for applying generally accepted accounting principles to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments in ASU 2020-04 are effective for all entities as of March 12, 2020 through December 31, 2022. An entity may elect to apply the amendments for contract modifications by Topic or Industry Subtopic as of any date from the beginning an interim period that includes or is subsequent to March 12, 2020, or prospectively from the date that the financial statements are available to be issued. Once elected for a Topic or an Industry Subtopic, the amendments must be applied prospectively for all eligible contract modifications for that Topic or Industry Subtopic. The Company may elect to apply ASU 2020-04 as its contracts referenced in London Interbank Offered Rate (“LIBOR”) are impacted by reference rate reform. The Company is currently evaluating the impact of the adoption of this ASU on the Company’s consolidated financial statements. In August 2020, the FASB issued ASU No. 2020-06, Debt—Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity's Own Equity (Subtopic 815-40)—Accounting For Convertible Instruments and Contracts in an Entity's Own Equity (“ASU 2020-06”). ASU 2020-06 simplifies accounting for convertible instruments by removing major separation models required under current GAAP. Consequently, more convertible debt instruments will be reported as a single liability instrument with no separate accounting for embedded conversion features. ASU 2020-06 removes certain settlement conditions that are required for equity contracts to qualify for the derivative scope exception, which will permit more equity contracts to qualify for it. ASU 2020-06 also simplifies the diluted net income per share calculation in certain areas. This ASU is effective for the Company for fiscal years beginning after December 15, 2023, and interim periods within those fiscal years, with early adoption permitted for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. The Company is currently evaluating the impact of the adoption of this principle on the Company’s consolidated financial statements. In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses. This new guidance will require financial instruments to be measured at amortized cost, and trade accounts receivable to be presented at the net amount expected to be collected. The new model requires an entity to estimate credit losses based on historical information, current information and reasonable and supportable forecasts, including estimates of prepayments. In November 2019, the FASB issued ASU 2019-10, according to which, the new standard is effective for public business entities that meet the definition of an SEC filer, excluding entities eligible to be smaller reporting companies (“SRC”) as defined by the SEC, for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years. For all other entities, including the Company, the new standard is effective for fiscal years beginning after December 15, 2022, and interim periods within that fiscal year. Early adoption is permitted. The Company is currently evaluating the impact of the new standard on the Company’s consolidated financial statements.

- Definition

The entire disclosure for change in accounting principle. Includes, but is not limited to, nature, reason, and method of adopting amendment to accounting standards or other change in accounting principle.

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+ Details

Stockholders' Equity - Shares Reserved for Future Issuance (Details) - shares	Mar. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	8,440,914	6,877,197
Common stock options issued and outstanding
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	2,759,165	2,923,403
Common stock available for future grants
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	4,604,812	3,233,794
Common stock available for ESPP
Class of Stock [Line Items]
Shares reserved for future issuance (in shares)	1,076,937	720,000

Balance Sheet Components - Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 1,849	$ 1,849
Accumulated Amortization	(1,479)	(1,449)
Net Carrying Value	370	400
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1,658	1,658
Accumulated Amortization	(1,326)	(1,299)
Net Carrying Value	332	359
Trademarks
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	191	191
Accumulated Amortization	(153)	(150)
Net Carrying Value	$ 38	$ 41

Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
Revenue Recognition (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Deferred revenue	$ 0.1	$ 0.1	$ 0.2
Revenue recognized	$ 0.1	$ 0.2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities
Net loss	$ (12,045)	$ (7,163)
Adjustments to reconcile net loss to net cash used in operating activities
Stock-based compensation expense	2,268	209
Change in fair value of derivative liabilities	0	(330)
Allowance for doubtful accounts	(1)	(8)
Inventory write-downs	453	95
Depreciation and amortization expense	141	116
Amortization of debt discount and debt issuance costs	39	211
Amortization of premiums and discounts on short-term marketable securities	4	(33)
Non-cash lease expense	572	213
Net changes in operating assets and liabilities:
Accounts receivable	(1,014)	912
Inventory	(1,630)	(2,189)
Prepaid expenses and other current assets	404	246
Other assets	8	229
Accounts payable	302	(163)
Accrued liabilities	1,275	(2,049)
Income taxes payable	30	20
Lease liabilities	(496)	(61)
Deferred tax liability	10	19
Deferred revenue	8	(123)
Net cash used in operating activities	(9,672)	(9,849)
Cash flows from investing activities
Purchases of investments	(12,289)	0
Maturities of short-term marketable securities	0	10,105
Purchases of property and equipment	(242)	(81)
Net cash (used in) provided by investing activities	(12,531)	10,024
Cash flows from financing activities
Proceeds from borrowing under term loans, net of payment of lender fees and costs	0	16,764
Repayment of term loans	0	(17,248)
Debt issuance cost	(30)	(82)
Payments of deferred offering costs	0	(400)
Proceeds from exercise of warrants for Series C-1 convertible preferred stock	0	2,261
Proceeds from exercise of common stock options	69	13
Payments for the repurchase of early exercised common stock options	(26)	0
Net cash provided by financing activities	13	1,308
Effect of exchange rate changes on cash and cash equivalents	(88)	222
Net (decrease) increase in cash and cash equivalents	(22,278)	1,705
Cash, cash equivalents and restricted cash, at beginning of the period	231,792	14,767
Cash, cash equivalents and restricted cash, at end of the period	209,514	16,472
Reconciliation of cash, cash equivalents and restricted cash to consolidated balance sheets:
Cash, cash equivalents and restricted cash in consolidated balance sheets	209,514	16,472
Supplemental non-cash items:
Lapse in repurchase rights of common stock	66	2
Purchases of property and equipment in accounts payable	144	18
Amount receivable from exercise of common stock options	204	0
Supplemental disclosure of cash flow information:
Cash paid for income taxes	23	45
Cash paid for interest	$ 178	$ 2,574

Net Loss per Share Attributable to Common Stockholders - Computation of Basic and Diluted Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator
Net loss attributable to common stockholders	$ (12,045)	$ (7,163)
Denominator
Weighted-average common stock outstanding (in shares)	35,702,465	2,104,721
Less: weighted-average common shares subject to repurchase (in shares)	(331,705)	(198,006)
Weighted-average shares used in computing net loss per share attributable to common stockholder, basic and diluted (in shares)	35,370,760	1,906,715
Net loss per share attributable common stockholders, basic	$ (0.34)	$ (3.76)
Net loss per share attributable to common stockholders, diluted	$ (0.34)	$ (3.76)

- Definition

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

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+ Details

Segment Information (Tables)

3 Months Ended

Mar. 31, 2021

Segment Reporting [Abstract]

Schedule of Revenue by Geographic Area

The following table sets forth the Company’s revenue by geographic area (in thousands):


	Three Months Ended March 31,
	2021		2020
United States	4,289		4,489
Europe, Middle-East and Africa (“EMEA”)	$	4,044	$	3,457
Asia Pacific	911		633
Other International	—		39
Total	$	9,244	$	8,618

Schedule of Long-lived Assets by Geographic Area

The following table sets forth the Company’s long-lived assets by geographic area (in thousands):


	March 31		December 31,
	2021		2020
United States	$	1,749	$	1,437
EMEA	43		29
Asia Pacific	7		8
Total	$	1,799	$	1,474

Long Term Debt and Convertible Notes (Tables)

3 Months Ended

Mar. 31, 2021

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

The CIBC Loan consists of the following (in thousands):


	March 31,		December 31,
	2021		2020
Term loan	$	17,000	$	17,000
Less: debt issuance costs	(199)		(196)
Term loan	$	16,801	$	16,804

Schedule of Contractual Maturities of Financing Obligations

As of March 31, 2021, the aggregate future payments under the CIBC Loan and Credit Agreement (including interest payments) are as follows (in thousands):


2021 (remaining nine months)	$	544
2022	5,369
2023	6,078
2024	5,837
2025	1,480
Total	19,308
Less: unamortized debt discount	(198)
Less: interest	(1,777)
Term loan and credit agreement	$	17,333

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

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+ Details

Stockholders' Equity - Stock Option Activity (Details)	3 Months Ended
Stockholders' Equity - Stock Option Activity (Details)	Mar. 31, 2021 $ / shares shares
Number of Shares
Balance, beginning of period (in shares) \| shares	2,923,403
Options granted (in shares) \| shares	8,600
Options exercised (in shares) \| shares	(122,856)
Options canceled (in shares) \| shares	(49,982)
Balance, end of period (in shares) \| shares	2,759,165
Weighted Average Exercise Price
Balance, beginning of period (in dollars per share) \| $ / shares	$ 4.72
Options granted (in dollars per share) \| $ / shares	62.34
Options exercised (in dollars per share) \| $ / shares	2.22
Options canceled (in dollars per share) \| $ / shares	2.44
Balance, end of period (in dollars per share) \| $ / shares	$ 5.05

Stockholders' Equity - Options Vested and Expected to Vest (Details)	3 Months Ended
	Mar. 31, 2021 $ / shares shares
Number of Shares
Options vested (in shares) \| shares	1,223,414
Options vested and expected to vest (in shares) \| shares	2,759,165
Weighted Average Exercise Price
Options vested (in dollars per share) \| $ / shares	$ 2.20
Options vested and expected to vest (in dollars per share) \| $ / shares	$ 5.05
Weighted Average Contractual Life (in Years)
Options vested	4 years 10 months 28 days
Options vested and expected to vest	7 years 3 months 18 days

Long Term Debt and Convertible Notes - CIBC Loan Narrative (Details)		1 Months Ended		3 Months Ended
	Feb. 20, 2020 USD ($) payment	Mar. 31, 2021 USD ($)	Apr. 30, 2020 USD ($)	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)
Debt Instrument [Line Items]
Payment of fees to lender and third parties				$ 30,000	$ 82,000
Amortization of debt discount and debt issuance costs				$ 39,000	211,000
CIBC Agreement \| Medium-term Notes
Debt Instrument [Line Items]
Debt instrument, face amount including accordion feature	$ 32,000,000.0
Debt term	5 years
Interest payments term	24 months
Principal and interest payments term	36 months
Interest period extension term	36 months
Interest-only period, training period of revenue requirement	3 months
Revenue threshold for interest period extension term option	$ 20,000,000.0
Fee amount			$ 200,000
Number of periodic payments \| payment	36
Payment of fees to lender and third parties	$ 400,000	$ 100,000
Effective interest rate		4.78%		4.78%
Cash and cash equivalents trigger for revenue requirement	$ 100,000,000.0
Minimum percentage of revenue requirement, trailing period of revenue	3 months
Minimum percentage of revenue requirement	80.00%
Unrestricted cash requirement period	4 months
Amortization of debt discount and debt issuance costs				$ 100,000	100,000
Interest expense				$ 200,000	$ 100,000
CIBC Agreement \| Medium-term Notes \| Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.00%
CIBC Agreement, Tranche A \| Medium-term Notes
Debt Instrument [Line Items]
Proceeds from issuance of debt	$ 17,000,000.0
CIBC Agreement, Tranche B \| Medium-term Notes
Debt Instrument [Line Items]
Accordion feature on face amount of debt	8,000,000.0
Trailing period of revenue			6 months
Revenue threshold for additional borrowing			$ 15,000,000.0
CIBC Agreement, Tranche C \| Medium-term Notes
Debt Instrument [Line Items]
Accordion feature on face amount of debt	$ 7,000,000.0
Trailing period of revenue	6 months
Revenue threshold for additional borrowing	$ 20,000,000.0
CIBC Agreement, Tranche C \| Medium-term Notes \| Prime Rate
Debt Instrument [Line Items]
Basis spread on variable rate	1.50%
CIBC Agreement, Tranche B Or Tranche C \| Medium-term Notes
Debt Instrument [Line Items]
Structuring fee percentage			1.00%

Long Term Debt and Convertible Notes - CIBC Loan Components Of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Term loan	$ 19,308
Less: debt issuance costs	(198)
Term loan and credit agreement	17,333
CIBC Agreement \| Medium-term Notes
Debt Instrument [Line Items]
Term loan	17,000	$ 17,000
Less: debt issuance costs	(199)	(196)
Term loan and credit agreement	$ 16,801	$ 16,804

Stockholders' Equity

3 Months Ended

Mar. 31, 2021

Equity [Abstract]

Stockholders' Equity

Stockholders’ Equity

Common Stock

As of March 31, 2021 and December 31, 2020, the Company’s certificate of incorporation authorized the Company to issue up to 200,000,000 shares of common stock. Common stockholders are entitled to dividends as and when declared by the Board of Directors, subject to the rights of holders of all classes of stock outstanding having priority

rights as to dividends. There have been no dividends declared to date. The holder of each share of common stock is entitled to one vote.

Shares Reserved for Future Issuance

The Company has reserved shares of common stock for future issuances as follows:


	March 31	December 31,
	2021	2020
Common stock options issued and outstanding	2,759,165	2,923,403
Common stock available for future grants	4,604,812	3,233,794
Common stock available for ESPP	1,076,937	720,000
Total	8,440,914	6,877,197

Stock Option Plan

A summary of stock option activity for the three months ended March 31, 2021 is set forth below:


	Outstanding Options
	Number of Shares	Weighted Average Exercise Price
Balance, January 1, 2021	2,923,403	$	4.72
Options granted	8,600	62.34
Options exercised	(122,856)	2.22
Options canceled	(49,982)	2.44
Balance, March 31, 2021	2,759,165	$	5.05

The weighted average exercise price and aggregate intrinsic value of options outstanding at March 31, 2021 was $5.05 per share and $112.5 million, respectively.


	March 31, 2021
	Number of Shares	Weighted Average Exercise Price		Weighted Average Contractual Life (in Years)
Options vested	1,223,414	$	2.20	4.91
Options vested and expected to vest	2,759,165	$	5.05	7.30

Total intrinsic value of options vested as of March 31, 2021 was $53.3 million.

Early Exercise of Stock Options

Under the terms of the individual option grants, all options are fully exercisable on the grant date, subject to the Company’s repurchase right at the original exercise price. Accordingly, options may be exercised prior to vesting. The shares are subject to the Company’s lapsing repurchase right upon termination of employment or over the options’ vesting period of generally four years at the original purchase price. The proceeds initially are recorded in other liabilities from the early exercise of stock options and are reclassified to additional paid-in capital as the Company’s repurchase right lapses. During the three months ended March 31, 2021, the Company repurchased 12,945 shares of common stock for less than $0.1 million. During the three months ended March 31, 2020, the Company did not repurchase shares of common stock. As of March 31, 2021 and December 31, 2020, 303,899 and

355,677 shares, respectively, were subject to repurchase, with an aggregate exercise price of $0.5 million and $0.6 million, respectively, and were recorded in other current liabilities.

Restricted Stock Units

Activity with respect to restricted stock units was as follows:


	Number of Shares Underlying Outstanding Restricted Stock	Weighted Average Grant Date Fair Value
Unvested, January 1, 2021	—	$	—
Granted	6,300	$	60.17
Unvested, March 31, 2021	6,300	$	60.17

Total Stock-Based Compensation

Stock-based compensation expense is reflected in the statements of operations and comprehensive loss as follows (in thousands):


	Three Months Ended March 31,
	2021		2020
Cost of goods sold	$	90	$	15
Research and development	318		15
Selling, general and administrative	1,860		179
Total	$	2,268	$	209

The above stock-based compensation expense related to the following equity-based awards (in thousands):


	Three Months Ended March 31,
	2021		2020
Stock options and restricted stock units	$	1,039	$	209
ESPP	1,229		—
Total	$	2,268	$	209

As of March 31, 2021, there was $14.1 million of unrecognized compensation costs related to non-vested common stock options and restricted stock units, expected to be recognized over a weighted-average period of 2.18 years.

As of March 31, 2021, the Company had unrecognized employee stock-based compensation relating to ESPP awards of approximately $0.8 million, which is expected to be recognized over a weighted-average period of 0.2 years.

Fair Value Measurements - Unrealized Gains and Losses and Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	$ 12,285
Unrealized Losses	(3)
Unrealized Gains	0
Fair Value	12,282
Amounts recognized on the consolidated balance sheet
Short-term marketable securities	9,784	$ 0
Long-term marketable securities	2,498	0
Marketable securities	13,282	$ 0
U.S. Treasury bonds
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	507
Unrealized Losses	0
Unrealized Gains	0
Fair Value	507
U.S. Government agency bonds
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	3,009
Unrealized Losses	(1)
Unrealized Gains	0
Fair Value	3,008
Corporate bonds
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	774
Unrealized Losses	(1)
Unrealized Gains	0
Fair Value	773
Commercial paper
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	7,995
Unrealized Losses	(1)
Unrealized Gains	0
Fair Value	7,994
Amounts recognized on the consolidated balance sheet
Cash equivalents	$ 1,000

Balance Sheet Components - Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Raw materials	$ 3,043	$ 3,342
Work in process	313	227
Finished goods	8,560	7,172
Total inventory	$ 11,916	$ 10,741