Eargo (EAR) 10-Q 20 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Nov. 18, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Registrant Name	Eargo, Inc.
Entity Central Index Key	0001719395
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Current Reporting Status	No
Entity Interactive Data Current	Yes
Entity Common Stock, Shares Outstanding		38,186,515
Entity Bankruptcy Proceedings, Reporting Current	true
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	EAR
Security Exchange Name	NASDAQ
Entity File Number	001-39616
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-3879805
Entity Address, Address Line One	1600 Technology Drive
Entity Address, Address Line Two	6th Floor
Entity Address, City or Town	San Jose
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	95110
City Area Code	650
Local Phone Number	351-7700
Document Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 70,224	$ 13,384
Accounts receivable, net	2,576	2,051
Inventories	3,289	2,880
Prepaid expenses and other current assets	1,379	1,598
Total current assets	77,468	19,913
Operating lease right-of-use assets	1,369
Property and equipment, net	6,946	5,400
Other assets	2,304	1,992
Total assets	88,087	27,305
Current liabilities:
Accounts payable	6,658	5,428
Accrued expenses	10,809	9,939
Long-term debt, current portion		4,800
Other current liabilities	2,079	1,717
Deferred revenue, current	441	406
Lease liability, current portion	1,097
Total current liabilities	21,084	22,290
Lease liability, noncurrent portion	412
Deferred revenue, noncurrent portion	17	269
Long-term debt, noncurrent portion	14,502	7,446
Convertible preferred stock warrant liability	544	396
Other liabilities		127
Total liabilities	36,559	30,528
Commitments and contingencies (Note 5)
Convertible preferred stock, $0.0001 par value; 73,108,323 and 36,269,166 shares authorized as of September 30, 2020 and December 31, 2019, respectively; 24,229,281 and 11,825,812 issued and outstanding as of September 30, 2020 and December 31, 2019, respectively	223,125	152,880
Stockholders’ deficit:
Additional paid in capital	15,662	3,100
Accumulated deficit	(187,259)	(159,203)
Total stockholders’ deficit	(171,597)	(156,103)
Total liabilities, convertible preferred stock and stockholders’ deficit	$ 88,087	$ 27,305

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Convertible preferred stock, par value	$ 0.0001	$ 0.0001
Convertible preferred stock, shares authorized	73,108,323	36,269,166
Convertible preferred stock, shares issued	24,229,281	11,825,812
Convertible preferred stock, shares outstanding	24,229,281	11,825,812
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	110,000,000	55,190,000
Common stock, shares issued	534,599	265,943
Common stock, shares outstanding	534,599	265,943

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Revenue, net	$ 18,186	$ 7,730	$ 46,776	$ 22,175
Cost of revenue	5,434	3,583	15,295	11,033
Gross profit	12,752	4,147	31,481	11,142
Operating expenses:
Research and development	2,871	3,219	7,888	8,781
Sales and marketing	12,354	9,290	34,041	24,698
General and administrative	5,163	3,683	14,498	8,781
Total operating expenses	20,388	16,192	56,427	42,260
Loss from operations	(7,636)	(12,045)	(24,946)	(31,118)
Other income (expense), net:
Interest income	3	136	26	555
Interest expense	(279)	(218)	(1,422)	(492)
Other income (expense), net	(187)	(30)	(87)	(84)
Loss on extinguishment of debt	(1,627)		(1,627)
Total other income (expense), net	(2,090)	(112)	(3,110)	(21)
Loss before income taxes	(9,726)	(12,157)	(28,056)	(31,139)
Net loss and comprehensive loss	$ (9,726)	(12,157)	(28,056)	(31,139)
Net income (loss) attributable to common stockholders, basic and diluted		$ (12,157)	$ (18,216)	$ (31,139)
Net income (loss) per share attributable to common stockholders, basic and diluted		$ (46.26)	$ (57.73)	$ (122.74)
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, basic and diluted	398,895	262,785	315,546	253,701

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit (Unaudited) - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Series D Convertible Preferred Stock	Series E Convertible Preferred Stock	Common Stock	Additional Paid-in Capital	Accumulated Deficit
Beginning balance at Dec. 31, 2018	$ (112,999)					$ 1,718	$ (114,717)
Temporary equity, Beginning balance, Shares at Dec. 31, 2018		11,761,159
Temporary equity, Beginning balance at Dec. 31, 2018		$ 152,015
Beginning balance, Shares at Dec. 31, 2018					231,831
Issuance of convertible preferred stock, net of issuance costs			$ 865
Issuance of convertible preferred stock, net of issuance costs, Shares			64,653
Stock-based compensation	107					107
Exercise of stock options	36					36
Exercise of stock options, Shares					27,557
Net loss and comprehensive loss	(9,223)						(9,223)
Ending balance at Mar. 31, 2019	(122,079)					1,861	(123,940)
Temporary equity, Ending balance, Shares at Mar. 31, 2019		11,825,812
Temporary equity, Ending balance at Mar. 31, 2019		$ 152,880
Ending balance, Shares at Mar. 31, 2019					259,388
Beginning balance at Dec. 31, 2018	(112,999)					1,718	(114,717)
Temporary equity, Beginning balance, Shares at Dec. 31, 2018		11,761,159
Temporary equity, Beginning balance at Dec. 31, 2018		$ 152,015
Beginning balance, Shares at Dec. 31, 2018					231,831
Net loss and comprehensive loss	(31,139)
Ending balance at Sep. 30, 2019	(143,101)					2,755	(145,856)
Temporary equity, Ending balance, Shares at Sep. 30, 2019		11,825,812
Temporary equity, Ending balance at Sep. 30, 2019		$ 152,880
Ending balance, Shares at Sep. 30, 2019					262,912
Beginning balance at Mar. 31, 2019	(122,079)					1,861	(123,940)
Temporary equity, Beginning balance, Shares at Mar. 31, 2019		11,825,812
Temporary equity, Beginning balance at Mar. 31, 2019		$ 152,880
Beginning balance, Shares at Mar. 31, 2019					259,388
Stock-based compensation	433					433
Exercise of stock options	4					4
Exercise of stock options, Shares					3,220
Net loss and comprehensive loss	(9,759)						(9,759)
Ending balance at Jun. 30, 2019	(131,401)					2,298	(133,699)
Temporary equity, Ending balance, Shares at Jun. 30, 2019		11,825,812
Temporary equity, Ending balance at Jun. 30, 2019		$ 152,880
Ending balance, Shares at Jun. 30, 2019					262,608
Stock-based compensation	457					457
Exercise of stock options, Shares					304
Net loss and comprehensive loss	(12,157)						(12,157)
Ending balance at Sep. 30, 2019	(143,101)					2,755	(145,856)
Temporary equity, Ending balance, Shares at Sep. 30, 2019		11,825,812
Temporary equity, Ending balance at Sep. 30, 2019		$ 152,880
Ending balance, Shares at Sep. 30, 2019					262,912
Beginning balance at Dec. 31, 2019	$ (156,103)					3,100	(159,203)
Temporary equity, Beginning balance, Shares at Dec. 31, 2019	11,825,812	11,825,812
Temporary equity, Beginning balance at Dec. 31, 2019	$ 152,880	$ 152,880
Beginning balance, Shares at Dec. 31, 2019					265,943
Stock-based compensation	525					525
Exercise of stock options	8					8
Exercise of stock options, Shares					4,188
Net loss and comprehensive loss	(11,738)						(11,738)
Ending balance at Mar. 31, 2020	(167,308)					3,633	(170,941)
Temporary equity, Ending balance, Shares at Mar. 31, 2020		11,825,812
Temporary equity, Ending balance at Mar. 31, 2020		$ 152,880
Ending balance, Shares at Mar. 31, 2020					270,131
Beginning balance at Dec. 31, 2019	$ (156,103)					3,100	(159,203)
Temporary equity, Beginning balance, Shares at Dec. 31, 2019	11,825,812	11,825,812
Temporary equity, Beginning balance at Dec. 31, 2019	$ 152,880	$ 152,880
Beginning balance, Shares at Dec. 31, 2019					265,943
Net loss and comprehensive loss	(28,056)
Ending balance at Sep. 30, 2020	$ (171,597)					15,662	(187,259)
Temporary equity, Ending balance, Shares at Sep. 30, 2020	24,229,281	24,229,281	3,896,711	12,403,469
Temporary equity, Ending balance at Sep. 30, 2020	$ 223,125	$ 223,125	$ 51,952	$ 80,084
Ending balance, Shares at Sep. 30, 2020					534,599
Beginning balance at Mar. 31, 2020	(167,308)					3,633	(170,941)
Temporary equity, Beginning balance, Shares at Mar. 31, 2020		11,825,812
Temporary equity, Beginning balance at Mar. 31, 2020		$ 152,880
Beginning balance, Shares at Mar. 31, 2020					270,131
Stock-based compensation	471					471
Exercise of stock options	18					18
Exercise of stock options, Shares					10,335
Net loss and comprehensive loss	(6,592)						(6,592)
Ending balance at Jun. 30, 2020	(173,411)					4,122	(177,533)
Temporary equity, Ending balance, Shares at Jun. 30, 2020		11,825,812
Temporary equity, Ending balance at Jun. 30, 2020		$ 152,880
Ending balance, Shares at Jun. 30, 2020					280,466
Issuance of convertible preferred stock, net of issuance costs				$ 67,267
Issuance of convertible preferred stock, net of issuance costs, Shares				10,513,921
Issuance of convertible preferred stock, upon extinguishment of convertible notes (Note 6)				$ 12,818
Issuance of convertible preferred stock, upon extinguishment of convertible notes, Shares				1,889,548
Gain on extinguishment of Series C and Series C-1 convertible preferred stock	9,840	$ (9,840)				9,840
Stock-based compensation	1,367					1,367
Exercise of stock options	333					333
Exercise of stock options, Shares					254,133
Net loss and comprehensive loss	(9,726)						(9,726)
Ending balance at Sep. 30, 2020	$ (171,597)					$ 15,662	$ (187,259)
Temporary equity, Ending balance, Shares at Sep. 30, 2020	24,229,281	24,229,281	3,896,711	12,403,469
Temporary equity, Ending balance at Sep. 30, 2020	$ 223,125	$ 223,125	$ 51,952	$ 80,084
Ending balance, Shares at Sep. 30, 2020					534,599

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit (Unaudited) (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2020	Mar. 31, 2019
Series E Convertible Preferred Stock
Series D convertible preferred stock, issuance costs	$ 4.1
Series D Convertible Preferred Stock
Series D convertible preferred stock, issuance costs		$ 0

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating activities:
Net loss	$ (28,056)	$ (31,139)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,805	1,011
Stock-based compensation	2,363	997
Non-cash interest expense and amortization of debt discount	1,178	200
Non-cash operating lease expense	838
Bad debt expense	2,135	44
Loss on extinguishment of debt	1,627
Change in fair value of warrant liability	(122)	84
Change in fair value of derivative liability	206
Changes in operating assets and liabilities:
Accounts receivable	(2,660)	(113)
Inventories	(409)	(1,110)
Prepaid expenses and other current assets	219	(199)
Other assets	963	(311)
Accounts payable	579	(585)
Accrued expenses	147	1,750
Other current liabilities	362	(172)
Deferred revenue	(217)	409
Operating lease liabilities	(883)
Other liabilities	(127)	(59)
Net cash used in operating activities	(20,052)	(29,193)
Investing activities:
Purchases of property and equipment	(844)	(1,616)
Capitalized software development costs	(2,601)	(1,017)
Net cash used in investing activities	(3,445)	(2,633)
Financing activities:
Proceeds from stock options exercised	359	40
Proceeds from debt financing	15,000	5,000
Proceeds from convertible preferred stock issuance, net of issuance costs	67,867	865
Proceeds from issuance of convertible notes, net of issuance costs	10,053
Proceeds from PPP loan	4,574
Repayment of PPP loan	(4,574)
Debt repayments	(12,720)
Payments of deferred offering costs	(222)
Net cash provided by financing activities	80,337	5,905
Net increase (decrease) in cash and cash equivalents and restricted cash	56,840	(25,921)
Cash and cash equivalents and restricted cash at beginning of period	13,384	51,201
Cash and cash equivalents and restricted cash at end of period	70,224	25,280
Supplemental disclosure of cash flow information:
Cash paid for interest	253	275
Non-cash operating activities:
Lease liability obtained in exchange for right-of-use asset	2,392
Non-cash investing and financing activities:
Property and equipment and capitalized software costs in accounts payable and accrued liabilities	421	307
Deferred offering costs in accounts payable and accrued liabilities	1,053
Convertible preferred stock issuance costs included in accounts payable	600
Derivative liability in connection with issuance of convertible promissory notes on issuance	2,879
Settlement of derivative liability in connection with extinguishment of convertible notes	3,085
Issuance of convertible preferred stock warrants in connection with debt financing	270	$ 41
Convertible Preferred Stock | Series E Convertible Preferred Stock
Non-cash investing and financing activities:
Issuance of Series E convertible preferred stock upon extinguishment of convertible notes	$ 12,818

Description of Business

Description of Business	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Description of Business	1. Description of business Eargo, Inc. (the “Company”) is a medical device company dedicated to improving the quality of life of people with hearing loss. The Eargo solution was developed to create a hearing aid that consumers actually want to use. The Company’s innovative product and go-to-market approach address the major challenges of traditional hearing aid adoption, including social stigma, accessibility and cost. Initial public offering On October 20, 2020, the Company closed its initial public offering (“IPO”) of its common stock in which the Company issued and sold 7,851,852 shares of its common stock, and concurrently sold an additional 1,177,777 shares upon the full exercise of the underwriters’ option to purchase additional shares. In connection with the IPO, including the underwriters’ option, the Company issued and sold an aggregate of 9,029,629 shares of common stock at $18.00 per share, raising approximately $148.1 million in proceeds, net of underwriting discounts and commissions of $11.4 million and estimated offering costs of $3.1 million, of which $1.3 million were incurred as of September 30, 2020. Immediately prior to the closing of the IPO, all outstanding shares of convertible preferred stock were converted into 28,196,388 shares of common stock. Further, all outstanding convertible preferred stock warrants were converted into warrants to purchase 137,812 shares of common stock (see Note 10). The condensed consolidated financial statements as of September 30, 2020, including share and per share amounts, do not give effect to the IPO or the conversion of the convertible preferred stock into common stock, as the IPO and such conversions were completed subsequent to September 30, 2020. Reverse stock split In October 2020, the Company’s board of directors approved an amended and restated certificate of incorporation to effect a reverse split of shares of the Company’s common stock and convertible preferred stock on a 3-for-1 basis (the “Reverse Stock Split”), which was filed and effective on October 8, 2020. The number of authorized shares and the par values of the common stock and convertible preferred stock were not adjusted as a result of the Reverse Stock Split. All references to common stock, options to purchase common stock, convertible preferred stock, warrants to purchase convertible preferred stock, share data, per share data and related information contained in the condensed consolidated financial statements have been retrospectively adjusted to reflect the effect of the Reverse Stock Split for all periods presented. Liquidity The Company has incurred losses and negative cash flows from operations since its inception and management expects to incur additional substantial losses in the foreseeable future. As of September 30, 2020, the Company had cash and cash equivalents of $70.2 million and an accumulated deficit of $187.3 million. The Company believes that its existing cash and cash equivalents as of September 30, 2020, together with the net proceeds of approximately $148.1 million received from its IPO (see Note 10), will be sufficient for the Company to continue as a going concern for at least one year from its unaudited condensed consolidated financial statements filed with the Securities and Exchange Commission (“SEC”). The Company’s future capital requirements will depend on many factors, including its growth rate, the timing and extent of its spending to support research and development activities and the timing and cost of establishing additional sales and marketing capabilities.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of significant accounting policies Basis of presentation and principles of consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and applicable rules and regulations SEC regarding interim financial reporting. All intercompany balances and transactions have been eliminated. The interim condensed consolidated balance sheet as of September 30, 2020, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2020 and 2019, the condensed consolidated statements of convertible preferred stock and stockholders’ deficit and the statements of cash flows for the nine months ended September 30, 2020 and 2019 are unaudited. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s consolidated financial position as of September 30, 2020 and its results of operations and comprehensive loss for the three and nine months ended September 30, 2020 and 2019, and cash flows for the nine months ended September 30, 2020 and 2019. The financial data and the other financial information contained in these notes to the condensed consolidated financial statements related to the three and nine months periods are also unaudited. The results of operations and comprehensive loss for the three and nine months ended September 30, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020 or for any other future annual or interim period. The condensed consolidated balance sheet as of December 31, 2019 included herein was derived from the audited financial statements as of that date. These condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements included in the prospectus dated October 15, 2020 (“Prospectus”) that forms a part of the Company's Registration Statements on Form S-1 (File No. 333-24907), as filed with the SEC pursuant to Rule 424(b)(4) promulgated under the Securities Act of 1933, as amended. Use of estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates, assumptions, and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates and assumptions made in the accompanying condensed consolidated financial statements include, but are not limited to, allowance for sales returns, the fair value of lease liabilities, the fair value of equity securities, the fair value of financial instruments, the allowance for doubtful accounts, net realizable value of inventory, accrued product warranty reserve, certain other accruals and recoverability of the Company’s net deferred tax assets and the related valuation allowance. Management periodically evaluates its estimates, which are based on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates. Concentration of credit risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of demand deposit accounts, money market accounts and accounts receivable, including credit card receivables. The Company maintains its cash and cash equivalents, which may, at times, exceed federally insured limits, with financial institutions of high credit standing. As of September 30, 2020, the Company has not experienced any losses on its deposit accounts and money market accounts. As of September 30, 2020, the Company does not believe there is significant financial risk from nonperformance by the issuers of the Company’s deposit accounts and money market accounts. Fair value measurement Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. The Company measures fair value based on a three-level hierarchy of inputs, of which the first two are considered observable and the last unobservable. Unobservable inputs reflect the Company’s own assumptions about current market conditions. The Company maximizes the use of observable inputs, where available, and minimizes the use of unobservable inputs when measuring fair value. The three-level hierarchy of inputs is as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2—Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices 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 assets or liabilities; and Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the condensed consolidated balance sheets for cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to their short-term nature. The fair value of the Company’s outstanding term loan is estimated using the net present value of the payments, discounted at an interest rate that is consistent with a market interest rate, which is a Level 2 input. The fair value of the outstanding term loan approximates the carrying amount as the term loan bears a floating rate that approximates the market interest rate. Accounts receivable, net Accounts receivable represents amounts due from third-party institutions for credit card and debit card transactions and trade accounts receivable. Accounts receivable are recorded at invoiced amounts, net of allowances for doubtful accounts. The allowance for doubtful accounts is based on the Company’s assessment of the collectibility of accounts. Management regularly reviews the adequacy of the allowance for doubtful accounts by considering the age of each outstanding invoice, each customer’s expected ability to pay, and the collection history with each customer, when applicable, to determine whether a specific allowance is appropriate. As of September 30, 2020 and December 31, 2019, the Company recorded an allowance for doubtful accounts of $2.3 million and $0.2 million, respectively. The allowance for doubtful accounts charges are recorded as a component of general and administrative expenses in the unaudited condensed consolidated statements of operations and comprehensive loss. Leases The Company adopted Accounting Standards Codification (“ASC”) Topic 842, “ Leases ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized based on the present value of lease payments over the lease term at the commencement date of the lease. ROU assets also include any initial direct costs incurred and any lease payments made at or before the lease commencement date, less any lease incentive received. As the Company’s leases do not provide an implicit interest rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The Company elected to exclude from its condensed consolidated balance sheet recognition of leases having a term of 12 months or less (short-term leases) and elected to not separate lease components and non-lease components for its real estate leases. The Company’s non-lease components are primarily related to property maintenance, which varies based on future outcomes, and is recognized in rent expense when incurred. Deferred offering costs Offering costs consisting of legal, accounting, printer, and filing fees related to the Company’s planned IPO are deferred and will be offset against proceeds from the IPO upon effectiveness of the offering. As of December 31, 2019, the Company recorded deferred offering costs of $1.2 million as other assets on the condensed consolidated balance sheets. In March 2020, the Company terminated its offering and expensed all of its deferred offering costs amounting to $1.6 million as a component of general and administrative expenses in the unaudited condensed consolidated statements of operations and comprehensive loss. As of September 30, 2020, the Company recorded deferred offering costs of $1.3 million as other assets on the condensed consolidated balance sheets. Upon closing of the IPO in October 2020, all deferred offering costs were offset against the IPO proceeds. Convertible preferred stock warrant liability The Company accounts for its convertible preferred stock warrants issued in connection with its various financing transactions based upon the characteristics and provisions of the instrument. Convertible preferred stock warrants classified as liabilities are recorded on the unaudited condensed consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value at each reporting period, with the changes in fair value recognized as other income (expense), net in the unaudited condensed consolidated statements of operations and comprehensive loss. The Company will continue to adjust the liability for changes in the fair value of these warrants until the earlier of the exercise of the warrants, the expiration of the warrants, or until such time as the warrants are no longer considered liability instruments. Upon the closing of the IPO in October 2020, the convertible preferred stock warrants were converted into warrants to purchase common stock and the warrant liabilities were reclassified to additional paid in capital. Derivative liability The Company’s convertible notes issued in 2020 (the “2020 Notes”) contain certain features that meet the definition of being embedded derivatives requiring bifurcation from the 2020 Notes as a separate compound financial instrument. The derivative liability is initially measured at fair value on issuance and is subject to remeasurement at each reporting period with changes in fair value recognized in other income (expense), net in the unaudited condensed consolidated statements of operations and comprehensive loss. In July 2020, the derivative liability was settled upon the extinguishment of the 2020 Notes. Revenue recognition The Company’s revenue is generated from the sale of products (hearing aid systems and related accessories) and services (extended warranties). These products and services are primarily sold directly to customers through the Eargo website and the Company sales representatives. Under ASC 606, revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services by following a five step process: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. Identify the contract with a customer . The Company generally considers completion of an Eargo sales order (which requires customer acceptance of the Company’s click-through terms and conditions for website sales and authorization of payment through credit card or another form of payment for sales made over the phone) as a customer contract provided that collection is considered probable. For payments that are not made upfront by credit card, the Company assesses insurance eligibility or customer creditworthiness based on credit checks, payment history, and/or other circumstances as appropriate. Identify the performance obligations in the contract . Product performance obligations include hearing aid systems and related accessories and service performance obligations include extended warranty coverage. The Company also offers customers a one-time replacement of certain components of the hearing aid system for a fee (i.e., “loss and damage policy”), which represents an option with material right. However, as the historical redemption rate under the policy has been low, the option is not accounted for as a separate performance obligation. The Company does not assess whether promised goods or services are performance obligations if they are immaterial in the context of the contract with the customer. The Company has elected to treat shipping and handling activities performed after a customer obtains control of products as a fulfillment activity. Determine the transaction price and allocation to performance obligations . The transaction price in the Company’s customer contracts consists of both fixed and variable consideration. Fixed consideration includes amounts to be contractually billed to the customer while variable consideration includes the 45-day right of return that applies to all products. To estimate product returns, the Company analyzes historical return levels, current economic trends, and changes in customer demand. Based on this information, the Company reserves a percentage of product sale revenue and accounts for the estimated impact as a reduction in the transaction price. Allocate the transaction price to the performance obligations in the contract. For contracts that contain multiple performance obligations, the Company allocates the transaction price to the performance obligations on a relative standalone selling price basis. Standalone selling prices are based on multiple factors including, but not limited to historical discounting trends for products and services, gross margin objectives, internal costs, competitor pricing strategies, and industry technology lifecycles. Recognize revenue when or as the Company satisfies a performance obligation . Revenue for products (hearing aid systems and related accessories) is recognized at a point in time, which is generally upon shipment. Revenue for services (extended warranty) is recognized over time on a ratable basis over the warranty period. Contract costs The Company applies the practical expedient to recognize the incremental costs of obtaining a contract as expense when incurred if the amortization period would be one year or less. These incremental costs include processing fees paid to third-party financing vendors, who provide the Company’s customers with the option to finance their purchase. If a customer elects to utilize this service, the Company receives a non-recourse upfront payment for the product sold, less processing fee withheld by the financing vendor. These processing fees are recognized in cost of revenue in the condensed consolidated statements of operations and comprehensive loss as incurred. Stock-based compensation The Company accounts for stock-based awards at fair value. The fair value of stock options is measured using the Black-Scholes option-pricing model. For stock-based awards that vest subject to the satisfaction of a service requirement, the fair value measurement date is the date of grant and the expense is recognized on a straight-line basis over the requisite service period. For stock-based awards with performance-based vesting conditions, the expense is recognized over the requisite service period using the accelerated attribution method. Prior to the Company’s IPO in October 2020, the Company had not recognized any stock-based compensation associated with grants that vest upon satisfaction of both a service condition and a performance condition that is satisfied upon the closing of the IPO as the performance condition was not considered probable. Upon the closing of the IPO, the Company recorded stock-based compensation (see Note 10 for further details) using the accelerated attribution method for the service period rendered from the date of grant through the closing of the IPO as the performance condition was achieved. The Company accounts for forfeitures as they occur. Net income (loss) per share attributable to common stockholders The Company follows the two-class method when computing net income (loss) per share as the Company has issued shares that meet the definition of participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. Basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration for potential dilutive securities. Diluted net income (loss) attributable to common stockholders is computed by adjusting net income (loss) attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net income (loss) per share is computed by dividing the net income (loss) by the weighted-average number of common shares and common share equivalents of potentially dilutive securities outstanding for the period. For purposes of the diluted net income (loss) per share calculation, convertible preferred stock, convertible notes, convertible preferred stock warrants and common stock options are considered to be potentially dilutive securities. Recently adopted accounting pronouncements In February 2016, the FASB issued Accounting Standards Update (“ASU”) 2016-02, Leases Leases In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement Recent accounting pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	3. Fair value measurements The following tables summarize the Company’s financial assets and liabilities that were measured at fair value on a recurring basis by level within the fair value hierarchy: September 30, 2020 Level 1 Level 2 Level 3 Total (in thousands) Liabilities: Convertible preferred stock warrant liability $ — $ — $ 544 $ 544 December 31, 2019 Level 1 Level 2 Level 3 Total (in thousands) Liabilities: Convertible preferred stock warrant liability $ — $ — $ 396 $ 396 Convertible preferred stock warrant liability The Company estimates the fair value of its convertible preferred stock warrant liability using the Black-Scholes option-pricing model, assumptions that are based on the individual characteristics of the warrants on the valuation date, and assumptions related to the fair value of the underlying stock, expected volatility, expected life, dividends, and risk-free interest rate. Due to the nature of these inputs, the warrants are considered a Level 3 liability. The fair value of the convertible preferred stock warrants as of September 30, 2020 was determined by probability-weighting the fair value under a scenario in which the Company completes an IPO and a scenario in which the Company stays private. The following table provides a summary of the change in the estimated fair value of the Company’s convertible preferred stock warrant liability: Total (in thousands) Balance — December 31, 2018 $ 81 Fair value of convertible preferred stock warrants issued in connection with debt financing 41 Change in fair value of warrant liability 84 Balance — September 30, 2019 $ 206 Total (in thousands) Balance — December 31, 2019 $ 396 Fair value of convertible preferred stock warrants issued in connection with debt financing 270 Change in fair value of warrant liability (122 ) Balance — September 30, 2020 $ 544 The fair value of the convertible preferred stock warrants was determined using the following assumptions as of each reporting date: September 30, December 31, Valuation assumptions: 2020 2019 Expected volatility 70%—71% 43%—67% Expected term 2.2—9.9 years 1.0—8.6 years Risk-free interest rate 0.14%—0.69% 1.59%—1.88% Dividend yield — — Derivative liability The 2020 Notes contain embedded derivatives requiring bifurcation as a single compound derivative instrument. The Company estimated the fair value of the derivative liability on issuance using a “with-and-without” method. The “with-and-without” methodology involves valuing the whole instrument on an as-is basis and then valuing the instrument without the individual embedded derivative. The difference between the entire instrument with the embedded derivative compared to the instrument without the embedded derivative was the fair value of the derivative liability on issuance. The estimated probability and timing of underlying events triggering the redemption features, conversion feature or put option contained within the 2020 Notes are inputs used to determine the estimated fair value of the entire instrument with the embedded derivative. The following table provides a summary of the change in the estimated fair value of the Company’s derivative liability: Total (in thousands) Balance — December 31, 2019 $ — Initial fair value of derivative liability 2,879 Change in fair value of derivative liability 206 Extinguishment of derivative liability (3,085 ) Balance — September 30, 2020 $ — In July 2020, the embedded derivative liability was settled upon the extinguishment of the 2020 Notes. Refer to Note 6 for further discussion.

Balance Sheet Components

Balance Sheet Components	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Components	4. Balance sheet components Inventories Inventories consist primarily of raw materials related to component parts and finished goods. The following is a summary of the Company’s inventories by category: September 30, December 31, 2020 2019 (in thousands) Raw materials $ 1,163 $ 1,115 Finished goods 2,126 1,765 Total inventories $ 3,289 $ 2,880 Property and equipment, net Property and equipment, net, consists of the following: September 30, December 31, 2020 2019 (in thousands) Tools and lab equipment $ 3,630 $ 2,885 Capitalized software 5,753 3,148 Furniture and fixtures 906 906 Leasehold improvements 757 757 Computer and equipment 288 423 11,334 8,119 Less accumulated depreciation and amortization (4,388 ) (2,719 ) Total property and equipment, net $ 6,946 $ 5,400 Depreciation and amortization for the three months ended September 30, 2020 and 2019 amounted to $0.7 million and $0.4 million, respectively, which includes amortization of capitalized software costs of $0.2 million and $0.1 million, respectively. Depreciation and amortization for the nine months ended September 30, 2020 and 2019 amounted to $1.8 million and $1.0 million, respectively, which includes amortization of capitalized software costs of $0.6 million and $0.2 million, respectively. Accrued expenses Accrued expenses consist of the following: September 30, December 31, 2020 2019 (in thousands) Allowance for sales returns $ 3,123 $ 3,759 Accrued compensation 4,428 2,739 Accrued vendor costs 438 2,776 Refunds due to customers 1,050 215 Accrued warranty reserve 1,770 450 Total accrued expenses $ 10,809 $ 9,939 Accrued warranty reserve The accrued warranty reserve consists of the following activity: Nine months ended September 30, Year ended December 31, 2020 2019 (in thousands) Accrued warranty reserve, beginning balance $ 450 $ 53 Charged to cost of revenue 2,318 1,589 Utilization of accrued warranty reserve (998 ) (1,192 ) Accrued warranty reserve, ending balance $ 1,770 $ 450

Commitment and Contingencies

Commitment and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitment and Contingencies	5. Commitment and contingencies Operating leases The Company has entered into non-cancelable operating leases for its offices. These leases generally contain scheduled rent increases and renewal options, which are not included in the determination of lease term unless the Company is reasonably certain that the renewal option would be exercised. As of September 30, 2020, the Company recorded an aggregate ROU asset of $1.4 million and an aggregate lease liability of $1.5 million in the accompanying unaudited condensed consolidated balance sheet. The ROU asset and corresponding lease liability were estimated using a weighted-average incremental borrowing rate of 7.1%. The weighted-average remaining lease term is 1.3 years. For the three and nine months ended September 30, 2020, the Company incurred $0.3 million and $0.9 million of operating lease costs. Variable lease payments for operating expenses and costs related to short-term leases were immaterial for the three and nine months ended September 30, 2020. Cash paid for amounts included in the measurement of operating lease liabilities were $0.3 million and $1.0 million for the three and nine months ended September 30, 2020. As of September 30, 2020, undiscounted future minimum lease payments due under the non-cancelable operating leases are as follows: Operating leases (in thousands) Remainder of 2020 $ 335 2021 1,074 2022 167 Total minimum future lease payments 1,576 Present value adjustment for minimum lease commitments (67 ) Total lease liability $ 1,509 As of December 31, 2019, undiscounted future minimum lease payments due under the non-cancelable operating leases (as defined by prior guidance) are as follows: Operating leases (in thousands) 2020 $ 1,349 2021 1,092 2022 167 Total minimum future lease payments $ 2,608 Litigation The Company may become involved in legal proceedings in the ordinary course of its business. The Company does not believe that any lawsuits or claims currently pending against it, individually or in the aggregate, are material, or will have a material adverse effect on its financial condition, results of operations or cash flows. The Company is subject to review from federal and state taxing authorities in order to validate the amounts of income, sales and/or use taxes which have been claimed and remitted. The Company has estimated exposure and established reserves for its estimated sales tax audit liability. In the normal course of business, the Company may agree to indemnify third parties with whom it enters into contractual relationships, including customers, lessors, and parties to other transactions with the Company, with respect to certain matters. The Company has agreed, under certain conditions, to hold these third parties harmless against specified losses, such as those arising from a breach of representations or covenants, other third-party claims that the Company’s products, when used for their intended purposes, infringe the intellectual property rights of such other third parties, or other claims made against certain parties. It is not possible to determine the maximum potential amount of liability under these indemnification obligations due to the Company’s limited history of prior indemnification claims and the unique facts and circumstances that are likely to be involved in each particular claim.

Debt Obligations

Debt Obligations	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Debt Obligations	6. Debt obligations 2018 Loan Agreement In June 2018, the Company entered into a Loan and Security Agreement (the “2018 Loan Agreement”) with Silicon Valley Bank. Under the terms of the 2018 Loan Agreement, Silicon Valley Bank made available to the Company term loans in an aggregate principal amount of $12.5 million and the Company borrowed $5.0 million in October 2018, $1.0 million in November 2018 and $1.0 million in December 2018. The term loans under the 2018 Loan Agreement mature in June 2022, with interest-only monthly payments for a specified period of time. Interest on the term loans accrued at a per annum rate equal to the Wall Street Journal prime rate minus 1.0% with a floor of 0.0%. Amendments to the 2018 Loan Agreement In January 2019, the Company executed the First Amendment to the Loan and Security Agreement, which extended the interest-only period for all borrowings under the agreement until January 2020. No other terms were amended. In June 2019, the Company borrowed an additional $5.0 million to increase the total principal balance to $12.0 million. In May 2020, the Company executed the Second Amendment to its Loan and Security Agreement, which deferred the principal payments due between May 2020 and July 2020 such that the deferred amounts will be repaid in equal monthly payments that started in August 2020 through the scheduled maturity of the loan in June 2022. The amendment was accounted for as a modification. In connection with the execution of the 2018 Loan Agreement, the Company issued warrants to purchase 30,173 shares of Series C convertible preferred stock. In connection with the June 2019 borrowing, the Company issued Silicon Valley Bank warrants to purchase 14,999 shares of Series C convertible preferred stock. The estimated fair value of the warrants at issuance was recorded as a discount on the loan and is amortized to interest expense over the term of the agreement using the effective interest method. In September 2020, the Company executed the Third Amendment to the Loan and Security Agreement (the “Third Amendment”), under which Silicon Valley Bank made available to the Company additional term loans in an aggregate principal amount of $20.0 million. The Company borrowed $15.0 million in September 2020 and used $10.2 million of the proceeds to repay the outstanding balance of $9.5 million and final payment fee of $0.7 million, or 6.0% of the original aggregate principal amount, on the existing term loan. The term loan under the Third Amendment matures in September 2024 with interest-only monthly payments until January 2022, which was extended to July 2022 upon the completion of the Company’s IPO in October 2020. The term loan accrues interest at a per annum rate equal to the Wall Street Journal prime rate plus 1.0% (4.25% as of September 30, 2020) and includes a final payment fee equal to 6.25% of the original aggregate principal amount. In connection with the execution of the Third Amendment, the Company issued Silicon Valley Bank a warrant to purchase 53,487 shares of Series E convertible preferred stock and authorized a warrant to purchase 17,829 additional shares of Series E convertible preferred stock to be issued upon any subsequent borrowing under the Third Amendment. The amendment was accounted for as a modification. Borrowings under the Third Amendment are collateralized by substantially all the assets of the Company, excluding intellectual property (but including rights to payment and proceeds thereof). The Third Amendment contains customary affirmative and restrictive covenants, including with respect to the Company’s ability to enter into fundamental transactions, incur additional indebtedness, grant liens, pay any dividend or make any distributions to its holders, make investments, merge or consolidate with any other person or engage in transactions with the Company’s affiliates, but do not include any financial covenants. The Company was in compliance with all of the covenants as of September 30, 2020. As of September 30, 2020, outstanding principal on the term loan and accrual for the final payment fee amounted to $15.0 million. During the nine months ended September 30, 2020 and 2019, the Company recognized interest expense related to the term loans of $0.5 million and $0.5 million, respectively, which is inclusive of amortization of debt discount. The effective interest rate was 8.06% as of September 30, 2020. Paycheck Protection Program loan On May 3, 2020, the Company executed a promissory note with MidFirst Bank, which provided for an unsecured loan in an aggregate principal amount of $4.6 million (the “PPP Loan”) pursuant to the Paycheck Protection Program under the Coronavirus Aid, Relief and Economic Security Act signed into law on March 27, 2020. The PPP Loan provided for a fixed interest rate of 1.0% per year with a maturity date of May 3, 2022. Monthly principal and interest payments due on the PPP Loan were deferred for a six-month period beginning from the date of disbursement of the PPP Loan. The PPP Loan allowed for prepayment by the Company at any time prior to maturity with no prepayment penalty. The Note contained customary event of default provisions. In August 2020, the Company repaid the PPP Loan in full in the amount of $4.6 million and terminated the related promissory note. During the three and nine months ended September 30, 2020, the Company recognized interest expense related to the PPP Loan of less than $0.1 million. 2020 Convertible Promissory Notes The Company issued an aggregate of $8.9 million in convertible promissory notes in March 2020 (the “2020 Notes”) and an additional aggregate of $1.2 million in April 2020 in a subsequent closing. The 2020 Notes accrued interest at a rate of 6.0% per annum and mature in March 2021. Upon maturity, the majority note holders have the option of having outstanding principal and unpaid accrued interest paid in cash or converted into Series D convertible preferred stock. In the event of a qualified sale of preferred stock or other equity securities resulting in aggregate gross proceeds to the Company of at least $15.0 million, all principal and accrued and unpaid interest under the 2020 Notes will automatically convert into the preferred stock issued in such a financing at a price per share equal to 80% of the lowest price per share of the preferred stock sold in the financing (redemption feature). In the event of an IPO, all principal and accrued and unpaid interest under the 2020 Notes will automatically convert into common stock at a price per share equal to 90% of the public offering price (redemption feature). The 2020 Notes also contained an option whereby in the event of a change of control event, at the option of the holders holding a majority in outstanding principal amount of the 2020 Notes, all principal and accrued and unpaid interest under the 2020 Notes will be convertible into the Company’s Series D convertible preferred stock at its original issue price (conversion feature) or, alternatively, such holders may elect to require the Company to pay to all 2020 Note holders an amount equal to the principal amount then outstanding and any accrued but unpaid interest plus an amount equal to 100% of the outstanding principal and accrued and unpaid interest (put option). The above mentioned redemption features, conversion feature and the put option contained in the 2020 Notes were determined to be embedded derivatives requiring bifurcation and separately accounted for as a single compound derivative instrument. Upon the issuances of the 2020 Notes, the Company recorded the fair value of the derivative liability of $2.9 million as a debt discount on the 2020 Notes and as a single compound derivative instrument. The debt discount was being amortized to interest expense using the effective interest method over the term of the 2020 Notes. During the nine months ended September 30, 2020, the Company recognized interest expense related to the 2020 Notes of $0.9 million, which is inclusive of amortization of debt discount. In July 2020, the 2020 Notes were redeemed whereby the outstanding principal balance of $10.1 million and accrued interest of $0.2 million was converted into 1,889,548 shares of Series E convertible preferred stock at a conversion price of $5.427 per share, a price equal to 80% of the $6.7836 per share paid by the investors in the Series E preferred stock financing. The redemption of the 2020 Notes was accounted for as a debt extinguishment, which resulted in a loss of $1.6 million that was recognized in other income (expense) in the consolidated statement of operations and comprehensive loss. The loss on extinguishment was calculated as the difference between (i) the fair value of the shares of Series E convertible preferred stock issued to settle the 2020 Notes and (ii) the carrying value of the 2020 Notes, net of the unamortized debt discount, plus the fair value of the derivative liability associated with the 2020 Notes at the time of extinguishment.

Convertible Preferred Stock

Convertible Preferred Stock	9 Months Ended
	Sep. 30, 2020
Temporary Equity Disclosure [Abstract]
Convertible Preferred Stock	7. Convertible preferred stock Series E convertible preferred stock issuances In July and August 2020, the Company issued an aggregate of 10,513,921 shares of Series E convertible preferred stock at a purchase price of $6.7836 per share in exchange for net proceeds of approximately $67.3 million. Contemporaneous with the initial closing of the Series E convertible preferred stock financing, the 2020 Notes (see Note 6) were redeemed whereby all of the outstanding principal and accrued interest amounting to $10.3 million was converted into 1,889,548 shares of Series E convertible preferred stock. In connection with the Series E convertible preferred stock financing, the Company amended and restated its certificate of incorporation to effect anti-dilution adjustments to prior series of convertible preferred stock that were issued, which changed the conversion prices for each share of convertible preferred stock from $27.87, $60.60, $9.0201, $9.0201, $7.2162 and $13.374 for the Series A convertible preferred stock, Series B convertible preferred stock, Series B-1 convertible preferred stock, Series C convertible preferred stock, Series C-1 convertible preferred stock and Series D convertible preferred stock, respectively, to $19.599, $39.6303, $8.0625, $8.0625, $6.9585, $10.7271, respectively. The amended and restated certificate of incorporation filed in connection with the Series E convertible preferred stock financing also amended the liquidation right held by holders of Series C and Series C-1 convertible preferred stock under which such holders were entitled to an aggregate liquidation amount per share from up to two times the original issue price to one times the original issuance price for the related series upon the event of a liquidation, dissolution, or winding up of the Company. This amendment of the liquidation right was determined to be significant using the qualitative approach. As such, the Company accounted for the amendment as an extinguishment of the outstanding Series C and Series C-1 convertible preferred stock and recorded a gain on extinguishment of $9.8 million on the date of the filing of the charter. The gain on the extinguishment of Series C and Series C-1 convertible preferred stock was calculated by taking the difference between the net carrying value of $59.7 million of Series C and Series C-1 convertible preferred stock immediately prior to the amendment of the liquidation right and the fair value of $49.9 million of the new of Series C and Series C-1 convertible preferred stock that for accounting purposes was deemed to be issued in connection with the amended and restated certificate of incorporation filed in connection with the Series E convertible preferred stock financing. The gain on extinguishment was recorded as a deemed contribution in equity and was recorded as a decrease to the net loss attributable to common stockholders for the three and nine months ended September 30, 2020 and as an increase to additional paid in capital. In October 2020, immediately prior to the completion of the IPO (see Note 10), all of the then-outstanding shares of convertible preferred stock automatically converted into 28,196,388 shares of common stock at the applicable conversion ratio then in effect. Convertible preferred stock consists of the following: September 30, 2020 Shares authorized Shares issued and outstanding Net carrying value Aggregate liquidation preference (in thousands, except share amounts) Series A convertible preferred stock 1,282,894 423,713 $ 16,130 $ 16,271 Series B convertible preferred stock 82,972 27,652 2,229 2,473 Series B-1 convertible preferred stock 2,539,761 838,892 22,871 23,003 Series C convertible preferred stock 11,311,611 3,725,354 29,274 33,603 Series C-1 convertible preferred stock 8,740,486 2,913,490 20,585 21,024 Series D convertible preferred stock 11,690,151 3,896,711 51,952 52,115 Series E convertible preferred stock 37,460,448 12,403,469 80,084 84,140 Total convertible preferred stock 73,108,323 24,229,281 $ 223,125 $ 232,629 The Company classifies its convertible preferred stock outside of total stockholders’ deficit because, in the event of certain “liquidation events” that are not solely within the control of the Company (including a merger, acquisition or sale of all or substantially all of the Company’s assets), the shares would become redeemable at the option of the holders. The Company did not adjust the carrying values of the convertible preferred stock to the deemed liquidation values of such shares since a liquidation event was not probable at any of the reporting dates. Subsequent adjustments to increase or decrease the carrying values to the ultimate liquidation values will be made only if and when it becomes probable that such liquidation event will occur.

Stock-based Compensation

Stock-based Compensation	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-based Compensation	8. Stock-based compensation Total stock-based compensation is as follows: Three months ended September 30, Nine months ended September 30, 2020 2019 2020 2019 (in thousands) Cost of revenue $ 9 $ 3 $ 17 $ 7 Research and development 295 83 550 183 Sales and marketing 344 73 594 126 General and administrative 719 298 1,202 681 Total stock-based compensation $ 1,367 $ 457 $ 2,363 $ 997 Stock-based compensation includes the impact of the Company repricing its stock options in August 2020 by canceling 1,574,243 option grants with a per share exercise price higher than $2.55 in exchange for 1,574,243 new option grants at an exercise price of $2.55 per share. Except for the change in exercise price, the new options had the same terms and conditions as the original options, including the contractual term, vesting schedule and the vesting start date. The total amount of stock-based compensation associated with the repricing is $1.2 million. During the three and nine months ended September 30, 2020, the Company recognized $0.4 million of stock-based compensation associated with the repricing, of which $0.3 million relates to options that were already vested on the date of modification. As of September 30, 2020, the Company has unrecognized stock-based compensation related to the repricing of $0.8 million to be expensed over the remaining vesting term of the new options. Determination of fair value The estimated grant-date fair value of the Company’s stock-based awards was calculated using the Black-Scholes option pricing model, based on the following assumptions: Three months ended September 30, Nine months ended September 30, Valuation assumptions: 2020 2019 2020 2019 Expected volatility 68%-71% 59% 60%-71% 58%-59% Expected term 5.1-7.0 years 6.0-6.1 years 5.1-7.0 years 5.0-10.0 years Risk-free interest rate 0.23%-0.46% 1.46%-1.72% 0.23% - 1.46%-2.51% Dividend yield — — — — Equity incentive plan As of September 30, 2020, the Company had reserved 7,104,636 shares of common stock for issuance under the 2010 Equity Incentive Plan (the “2010 Plan”). Activity under the 2010 Plan is set forth below: Number of shares Weighted average exercise price Weighted average remaining contractual term Aggregate intrinsic value (in years) (in thousands) Balance December 31, 2019 3,474,052 $ 2.93 8.55 $ 16,440 Grants 3,885,943 3.45 Exercises (268,656 ) 1.33 Cancelled/forfeited (329,827 ) 3.72 Balance September 30, 2020 6,761,512 $ 2.53 8.97 $ 21,620 Vested and exercisable at September 30, 2020 1,547,632 $ 1.71 7.51 $ 6,806 The weighted-average grant-date fair value of options granted during the nine months ended September 30, 2020 and 2019 were $3.05 and $2.75 per share, respectively. The aggregate intrinsic values of options outstanding and vested and exercisable were calculated as the difference between the exercise price of the options and the estimated fair value of the Company’s common stock, as determined by the Board of Directors. As of September 30, 2020, total unrecognized stock-based compensation related to outstanding unvested stock options was $16.3 million, which the Company expects to recognize over a remaining weighted-average period of 3.22 years. Performance awards In August 2020, the Company granted 1,129,270 stock options with both service-based vesting conditions and performance-based vesting conditions based on operating results that were deemed probable as of September 30, 2020. The grant date fair value of the awards was $3.7 million. The Company recorded $0.2 million in related stock-based compensation during the nine months ended September 30, 2020 based on the relative satisfaction of performance conditions based on performance to date. The performance-based conditions terminated upon the closing of the IPO in October 2020 per the original terms of the awards, with the service-based vesting conditions remaining in effect. In September 2020, the Company granted 212,489 stock options with both service-based and performance-based vesting conditions. The grant date fair value of the awards was $0.7 million. While the performance-based vesting condition was satisfied upon the completion of the IPO in October 2020, it was not considered probable until such event actually occurred and therefore not deemed probable as of September 30, 2020.

Net Income (Loss) Per Share Att

Net Income (Loss) Per Share Attributable To Common Stockholders	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Net Income (Loss) Per Share Attributable To Common Stockholders	9. Net income (loss) per share attributable to common stockholders The following outstanding potentially dilutive common stock equivalents have been excluded from the computation of diluted net income (loss) per share for the periods presented due to their anti-dilutive effect: Three months ended September 30, Nine months ended September 30, 2020 2019 2020 2019 Convertible preferred stock 28,196,388 13,710,242 28,196,388 13,710,242 Common stock options issued and outstanding 6,761,512 3,438,285 6,761,512 3,438,285 Convertible preferred stock warrants 137,812 73,913 137,812 73,913 Total 35,095,712 17,222,440 35,095,712 17,222,440 The following table sets forth the computation of basic and diluted net income (loss) per share attributable to common stockholders: Three months ended September 30, Nine months ended September 30, 2020 2019 2020 2019 (in thousands, except share and per share amounts) Numerator: Net loss $ (9,726 ) $ (12,157 ) $ (28,056 ) $ (31,139 ) Gain on extinguishment of Series C and Series C-1 convertible preferred stock 9,840 — 9,840 — Undistributed earnings allocated to participating securities (114 ) — — — Net income (loss) attributable to common stockholders, basic and diluted $ — $ (12,157 ) $ (18,216 ) $ (31,139 ) Denominator: Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, basic and diluted 398,895 262,785 315,546 253,701 Net income (loss) per share attributable to common stockholders, basic and diluted $ — $ (46.26 ) $ (57.73 ) $ (122.74 )

Subsequent Events (Unaudited)

Subsequent Events (Unaudited)	9 Months Ended
	Sep. 30, 2020
Subsequent Events [Abstract]
Subsequent Events	10. Subsequent events Reverse stock split In October 2020, the Company’s board of directors approved an amended and restated certificate of incorporation to effect a reverse split of shares of the Company’s common stock and convertible preferred stock on a 3-for-1 basis, which was effective as of October 8, 2020. The number of authorized shares and the par values of the common stock and convertible preferred stock were not adjusted as a result of the Reverse Stock Split. All references to common stock, options to purchase common stock, convertible preferred stock, warrants to purchase convertible preferred stock, share data, per share data and related information contained in the condensed consolidated financial statements have been retrospectively adjusted to reflect the effect of the Reverse Stock Split for all periods presented. Initial public offering On October 20, 2020, the Company closed its IPO, in which the Company issued and sold 7,851,852 shares of its common stock, and concurrently sold an additional 1,177,777 shares upon the full exercise of the underwriters’ option to purchase additional shares. In connection with the IPO, including the underwriters’ option to purchase additional shares, the Company issued and sold an aggregate of 9,029,629 shares of common stock at $18.00 per share, raising approximately $148.1 million in proceeds, net of underwriting discounts and commissions of $11.4 million and estimated offering costs of $3.1 million, of which $1.3 million were incurred as of September 30, 2020. Immediately prior to the closing of the IPO, all of the then-outstanding shares of convertible preferred stock automatically converted into 28,196,388 shares of common stock at the applicable conversion ratio then in effect. Further, all of the then-outstanding convertible preferred stock warrants were converted into warrants to purchase 137,812 shares of common stock and the convertible preferred stock warrant liability was reclassified to additional paid in capital. Upon the closing of the IPO, the Company recognized $0.1 million of cumulative stock-based compensation associated with stock options that begin vesting upon the achievement of a performance condition satisfied on the IPO for the service period rendered from the date of grant through the completion of the IPO. Amended and restated certificate of incorporation In connection with the IPO, the Company filed an amended and restated certificate of incorporation effective immediately prior to the closing of the IPO that authorized the issuance of up to 300,000,000 shares of common stock, par value $0.0001 per share, and 5,000,000 shares of undesignated preferred stock, par value $0.0001 per share. 2020 Equity Incentive Plan In October 2020, the Company’s Board of Directors and stockholders adopted and approved the 2020 Equity Incentive Plan, (the “2020 Plan”). The Company’s 2010 Stock Plan was terminated in connection with the IPO and no further grants will be made under the 2010 Plan from the date that the 2020 Plan became effective. The Company reserved 4,687,685 shares of common stock for future issuance under the 2020 Plan, from which options for 114,211 shares of common stock were granted upon the pricing of the IPO. 2020 Employee Stock Purchase Plan In October 2020, the Board of Directors and stockholders also adopted and approved the 2020 Employee Stock Purchase Plan (the “ESPP”). The Company reserved 726,773 shares of common stock for future issuance under the ESPP. Exercise of common stock warrants Subsequent to the closing of the IPO, in October 2020 and November 2020, Silicon Valley Bank net exercised 119,107 common stock warrants into 93,440 shares of common stock.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2020
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of presentation and principles of consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States (“GAAP”) and applicable rules and regulations SEC regarding interim financial reporting. All intercompany balances and transactions have been eliminated. The interim condensed consolidated balance sheet as of September 30, 2020, the condensed consolidated statements of operations and comprehensive loss for the three and nine months ended September 30, 2020 and 2019, the condensed consolidated statements of convertible preferred stock and stockholders’ deficit and the statements of cash flows for the nine months ended September 30, 2020 and 2019 are unaudited. The unaudited condensed consolidated financial statements have been prepared on the same basis as the annual consolidated financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to present fairly the Company’s consolidated financial position as of September 30, 2020 and its results of operations and comprehensive loss for the three and nine months ended September 30, 2020 and 2019, and cash flows for the nine months ended September 30, 2020 and 2019. The financial data and the other financial information contained in these notes to the condensed consolidated financial statements related to the three and nine months periods are also unaudited. The results of operations and comprehensive loss for the three and nine months ended September 30, 2020 are not necessarily indicative of the results to be expected for the year ending December 31, 2020 or for any other future annual or interim period. The condensed consolidated balance sheet as of December 31, 2019 included herein was derived from the audited financial statements as of that date. These condensed consolidated financial statements should be read in conjunction with the Company's audited consolidated financial statements included in the prospectus dated October 15, 2020 (“Prospectus”) that forms a part of the Company's Registration Statements on Form S-1 (File No. 333-24907), as filed with the SEC pursuant to Rule 424(b)(4) promulgated under the Securities Act of 1933, as amended.
Use of Estimates	Use of estimates The preparation of condensed consolidated financial statements in conformity with GAAP requires management to make estimates, assumptions, and judgments that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates and assumptions made in the accompanying condensed consolidated financial statements include, but are not limited to, allowance for sales returns, the fair value of lease liabilities, the fair value of equity securities, the fair value of financial instruments, the allowance for doubtful accounts, net realizable value of inventory, accrued product warranty reserve, certain other accruals and recoverability of the Company’s net deferred tax assets and the related valuation allowance. Management periodically evaluates its estimates, which are based on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Actual results may differ from those estimates.
Concentration of Credit Risk	Concentration of credit risk Financial instruments that potentially subject the Company to concentrations of credit risk consist of demand deposit accounts, money market accounts and accounts receivable, including credit card receivables. The Company maintains its cash and cash equivalents, which may, at times, exceed federally insured limits, with financial institutions of high credit standing. As of September 30, 2020, the Company has not experienced any losses on its deposit accounts and money market accounts. As of September 30, 2020, the Company does not believe there is significant financial risk from nonperformance by the issuers of the Company’s deposit accounts and money market accounts.
Fair Value Measurement	Fair value measurement Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability, or an exit price, in the principal or most advantageous market for that asset or liability in an orderly transaction between market participants on the measurement date. The Company measures fair value based on a three-level hierarchy of inputs, of which the first two are considered observable and the last unobservable. Unobservable inputs reflect the Company’s own assumptions about current market conditions. The Company maximizes the use of observable inputs, where available, and minimizes the use of unobservable inputs when measuring fair value. The three-level hierarchy of inputs is as follows: Level 1—Observable inputs such as unadjusted, quoted prices in active markets for identical assets or liabilities at the measurement date; Level 2—Observable inputs other than Level 1 prices, such as quoted prices for similar assets or liabilities, quoted prices 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 assets or liabilities; and Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. To the extent that the valuation is based on models or inputs that are less observable or unobservable in the market, the determination of fair value requires more judgment. Accordingly, the degree of judgment exercised by the Company in determining fair value is greatest for instruments categorized in Level 3. A financial instrument’s level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The carrying amounts reflected in the condensed consolidated balance sheets for cash and cash equivalents, accounts receivable, accounts payable and accrued liabilities approximate their fair values due to their short-term nature. The fair value of the Company’s outstanding term loan is estimated using the net present value of the payments, discounted at an interest rate that is consistent with a market interest rate, which is a Level 2 input. The fair value of the outstanding term loan approximates the carrying amount as the term loan bears a floating rate that approximates the market interest rate.
Accounts Receivable, Net	Accounts receivable, net Accounts receivable represents amounts due from third-party institutions for credit card and debit card transactions and trade accounts receivable. Accounts receivable are recorded at invoiced amounts, net of allowances for doubtful accounts. The allowance for doubtful accounts is based on the Company’s assessment of the collectibility of accounts. Management regularly reviews the adequacy of the allowance for doubtful accounts by considering the age of each outstanding invoice, each customer’s expected ability to pay, and the collection history with each customer, when applicable, to determine whether a specific allowance is appropriate. As of September 30, 2020 and December 31, 2019, the Company recorded an allowance for doubtful accounts of $2.3 million and $0.2 million, respectively. The allowance for doubtful accounts charges are recorded as a component of general and administrative expenses in the unaudited condensed consolidated statements of operations and comprehensive loss.
Leases	Leases The Company adopted Accounting Standards Codification (“ASC”) Topic 842, “ Leases ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized based on the present value of lease payments over the lease term at the commencement date of the lease. ROU assets also include any initial direct costs incurred and any lease payments made at or before the lease commencement date, less any lease incentive received. As the Company’s leases do not provide an implicit interest rate, the Company uses its incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense for lease payments is recognized on a straight-line basis over the lease term. The Company elected to exclude from its condensed consolidated balance sheet recognition of leases having a term of 12 months or less (short-term leases) and elected to not separate lease components and non-lease components for its real estate leases. The Company’s non-lease components are primarily related to property maintenance, which varies based on future outcomes, and is recognized in rent expense when incurred.
Deferred Offering Costs	Deferred offering costs Offering costs consisting of legal, accounting, printer, and filing fees related to the Company’s planned IPO are deferred and will be offset against proceeds from the IPO upon effectiveness of the offering. As of December 31, 2019, the Company recorded deferred offering costs of $1.2 million as other assets on the condensed consolidated balance sheets. In March 2020, the Company terminated its offering and expensed all of its deferred offering costs amounting to $1.6 million as a component of general and administrative expenses in the unaudited condensed consolidated statements of operations and comprehensive loss. As of September 30, 2020, the Company recorded deferred offering costs of $1.3 million as other assets on the condensed consolidated balance sheets. Upon closing of the IPO in October 2020, all deferred offering costs were offset against the IPO proceeds.
Convertible Preferred Stock Warrant Liability	Convertible preferred stock warrant liability The Company accounts for its convertible preferred stock warrants issued in connection with its various financing transactions based upon the characteristics and provisions of the instrument. Convertible preferred stock warrants classified as liabilities are recorded on the unaudited condensed consolidated balance sheets at their fair value on the date of issuance and remeasured to fair value at each reporting period, with the changes in fair value recognized as other income (expense), net in the unaudited condensed consolidated statements of operations and comprehensive loss. The Company will continue to adjust the liability for changes in the fair value of these warrants until the earlier of the exercise of the warrants, the expiration of the warrants, or until such time as the warrants are no longer considered liability instruments. Upon the closing of the IPO in October 2020, the convertible preferred stock warrants were converted into warrants to purchase common stock and the warrant liabilities were reclassified to additional paid in capital.
Derivative Liability	Derivative liability The Company’s convertible notes issued in 2020 (the “2020 Notes”) contain certain features that meet the definition of being embedded derivatives requiring bifurcation from the 2020 Notes as a separate compound financial instrument. The derivative liability is initially measured at fair value on issuance and is subject to remeasurement at each reporting period with changes in fair value recognized in other income (expense), net in the unaudited condensed consolidated statements of operations and comprehensive loss. In July 2020, the derivative liability was settled upon the extinguishment of the 2020 Notes.
Revenue Recognition	Revenue recognition The Company’s revenue is generated from the sale of products (hearing aid systems and related accessories) and services (extended warranties). These products and services are primarily sold directly to customers through the Eargo website and the Company sales representatives. Under ASC 606, revenue is recognized when promised goods or services are transferred to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services by following a five step process: (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when (or as) the entity satisfies a performance obligation. Identify the contract with a customer . The Company generally considers completion of an Eargo sales order (which requires customer acceptance of the Company’s click-through terms and conditions for website sales and authorization of payment through credit card or another form of payment for sales made over the phone) as a customer contract provided that collection is considered probable. For payments that are not made upfront by credit card, the Company assesses insurance eligibility or customer creditworthiness based on credit checks, payment history, and/or other circumstances as appropriate. Identify the performance obligations in the contract . Product performance obligations include hearing aid systems and related accessories and service performance obligations include extended warranty coverage. The Company also offers customers a one-time replacement of certain components of the hearing aid system for a fee (i.e., “loss and damage policy”), which represents an option with material right. However, as the historical redemption rate under the policy has been low, the option is not accounted for as a separate performance obligation. The Company does not assess whether promised goods or services are performance obligations if they are immaterial in the context of the contract with the customer. The Company has elected to treat shipping and handling activities performed after a customer obtains control of products as a fulfillment activity. Determine the transaction price and allocation to performance obligations . The transaction price in the Company’s customer contracts consists of both fixed and variable consideration. Fixed consideration includes amounts to be contractually billed to the customer while variable consideration includes the 45-day right of return that applies to all products. To estimate product returns, the Company analyzes historical return levels, current economic trends, and changes in customer demand. Based on this information, the Company reserves a percentage of product sale revenue and accounts for the estimated impact as a reduction in the transaction price. Allocate the transaction price to the performance obligations in the contract. For contracts that contain multiple performance obligations, the Company allocates the transaction price to the performance obligations on a relative standalone selling price basis. Standalone selling prices are based on multiple factors including, but not limited to historical discounting trends for products and services, gross margin objectives, internal costs, competitor pricing strategies, and industry technology lifecycles. Recognize revenue when or as the Company satisfies a performance obligation . Revenue for products (hearing aid systems and related accessories) is recognized at a point in time, which is generally upon shipment. Revenue for services (extended warranty) is recognized over time on a ratable basis over the warranty period. Contract costs The Company applies the practical expedient to recognize the incremental costs of obtaining a contract as expense when incurred if the amortization period would be one year or less. These incremental costs include processing fees paid to third-party financing vendors, who provide the Company’s customers with the option to finance their purchase. If a customer elects to utilize this service, the Company receives a non-recourse upfront payment for the product sold, less processing fee withheld by the financing vendor. These processing fees are recognized in cost of revenue in the condensed consolidated statements of operations and comprehensive loss as incurred.
Share-based Compensation	Stock-based compensation The Company accounts for stock-based awards at fair value. The fair value of stock options is measured using the Black-Scholes option-pricing model. For stock-based awards that vest subject to the satisfaction of a service requirement, the fair value measurement date is the date of grant and the expense is recognized on a straight-line basis over the requisite service period. For stock-based awards with performance-based vesting conditions, the expense is recognized over the requisite service period using the accelerated attribution method. Prior to the Company’s IPO in October 2020, the Company had not recognized any stock-based compensation associated with grants that vest upon satisfaction of both a service condition and a performance condition that is satisfied upon the closing of the IPO as the performance condition was not considered probable. Upon the closing of the IPO, the Company recorded stock-based compensation (see Note 10 for further details) using the accelerated attribution method for the service period rendered from the date of grant through the closing of the IPO as the performance condition was achieved. The Company accounts for forfeitures as they occur.
Net Income (Loss) per Share Attributable To Common Stockholders	Net income (loss) per share attributable to common stockholders The Company follows the two-class method when computing net income (loss) per share as the Company has issued shares that meet the definition of participating securities. The two-class method determines net income (loss) per share for each class of common and participating securities according to dividends declared or accumulated and participation rights in undistributed earnings. The two-class method requires income available to common stockholders for the period to be allocated between common and participating securities based upon their respective rights to receive dividends as if all income for the period had been distributed. Basic net income (loss) per share attributable to common stockholders is calculated by dividing the net income (loss) attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period, without consideration for potential dilutive securities. Diluted net income (loss) attributable to common stockholders is computed by adjusting net income (loss) attributable to common stockholders to reallocate undistributed earnings based on the potential impact of dilutive securities. Diluted net income (loss) per share is computed by dividing the net income (loss) by the weighted-average number of common shares and common share equivalents of potentially dilutive securities outstanding for the period. For purposes of the diluted net income (loss) per share calculation, convertible preferred stock, convertible notes, convertible preferred stock warrants and common stock options are considered to be potentially dilutive securities.
Recently Adopted and Recent Accounting Pronouncements	Recently adopted accounting pronouncements In February 2016, the FASB issued Accounting Standards Update (“ASU”) 2016-02, Leases Leases In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement Recent accounting pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis	The following tables summarize the Company’s financial assets and liabilities that were measured at fair value on a recurring basis by level within the fair value hierarchy: September 30, 2020 Level 1 Level 2 Level 3 Total (in thousands) Liabilities: Convertible preferred stock warrant liability $ — $ — $ 544 $ 544 December 31, 2019 Level 1 Level 2 Level 3 Total (in thousands) Liabilities: Convertible preferred stock warrant liability $ — $ — $ 396 $ 396
Embedded Derivatives
Summary of Change in Estimated Fair Value of Derivative Liability	The following table provides a summary of the change in the estimated fair value of the Company’s derivative liability: Total (in thousands) Balance — December 31, 2019 $ — Initial fair value of derivative liability 2,879 Change in fair value of derivative liability 206 Extinguishment of derivative liability (3,085 ) Balance — September 30, 2020 $ —
Convertible Preferred Stock Warrant Liability
Summary of Change in Estimated Fair Value of Convertible Preferred Stock Warrant Liability	The following table provides a summary of the change in the estimated fair value of the Company’s convertible preferred stock warrant liability: Total (in thousands) Balance — December 31, 2018 $ 81 Fair value of convertible preferred stock warrants issued in connection with debt financing 41 Change in fair value of warrant liability 84 Balance — September 30, 2019 $ 206 Total (in thousands) Balance — December 31, 2019 $ 396 Fair value of convertible preferred stock warrants issued in connection with debt financing 270 Change in fair value of warrant liability (122 ) Balance — September 30, 2020 $ 544
Summary of Fair Value of Convertible Preferred Stock Warrants Determined Using Following Assumptions	The fair value of the convertible preferred stock warrants was determined using the following assumptions as of each reporting date: September 30, December 31, Valuation assumptions: 2020 2019 Expected volatility 70%—71% 43%—67% Expected term 2.2—9.9 years 1.0—8.6 years Risk-free interest rate 0.14%—0.69% 1.59%—1.88% Dividend yield — —

Balance Sheet Components (Table

Balance Sheet Components (Tables)	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Summary of Inventories	The following is a summary of the Company’s inventories by category: September 30, December 31, 2020 2019 (in thousands) Raw materials $ 1,163 $ 1,115 Finished goods 2,126 1,765 Total inventories $ 3,289 $ 2,880
Summary of Property And Equipment, Net	Property and equipment, net, consists of the following: September 30, December 31, 2020 2019 (in thousands) Tools and lab equipment $ 3,630 $ 2,885 Capitalized software 5,753 3,148 Furniture and fixtures 906 906 Leasehold improvements 757 757 Computer and equipment 288 423 11,334 8,119 Less accumulated depreciation and amortization (4,388 ) (2,719 ) Total property and equipment, net $ 6,946 $ 5,400
Summary of Accrued Expenses	Accrued expenses consist of the following: September 30, December 31, 2020 2019 (in thousands) Allowance for sales returns $ 3,123 $ 3,759 Accrued compensation 4,428 2,739 Accrued vendor costs 438 2,776 Refunds due to customers 1,050 215 Accrued warranty reserve 1,770 450 Total accrued expenses $ 10,809 $ 9,939
Summary of Accrued Warranty Reserve	The accrued warranty reserve consists of the following activity: Nine months ended September 30, Year ended December 31, 2020 2019 (in thousands) Accrued warranty reserve, beginning balance $ 450 $ 53 Charged to cost of revenue 2,318 1,589 Utilization of accrued warranty reserve (998 ) (1,192 ) Accrued warranty reserve, ending balance $ 1,770 $ 450

Commitment and Contingencies (T

Commitment and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Schedule of Undiscounted Future Minimum Lease Payments Due under Non-cancelable Operating Leases	As of September 30, 2020, undiscounted future minimum lease payments due under the non-cancelable operating leases are as follows: Operating leases (in thousands) Remainder of 2020 $ 335 2021 1,074 2022 167 Total minimum future lease payments 1,576 Present value adjustment for minimum lease commitments (67 ) Total lease liability $ 1,509
Schedule of Undiscounted Future Minimum Lease Payments Due under Non-cancelable Operating Leases - Prior Guidance	As of December 31, 2019, undiscounted future minimum lease payments due under the non-cancelable operating leases (as defined by prior guidance) are as follows: Operating leases (in thousands) 2020 $ 1,349 2021 1,092 2022 167 Total minimum future lease payments $ 2,608

Convertible Preferred Stock (Ta

Convertible Preferred Stock (Tables)	9 Months Ended
	Sep. 30, 2020
Temporary Equity Disclosure [Abstract]
Summary of Convertible Preferred Stock	Convertible preferred stock consists of the following: September 30, 2020 Shares authorized Shares issued and outstanding Net carrying value Aggregate liquidation preference (in thousands, except share amounts) Series A convertible preferred stock 1,282,894 423,713 $ 16,130 $ 16,271 Series B convertible preferred stock 82,972 27,652 2,229 2,473 Series B-1 convertible preferred stock 2,539,761 838,892 22,871 23,003 Series C convertible preferred stock 11,311,611 3,725,354 29,274 33,603 Series C-1 convertible preferred stock 8,740,486 2,913,490 20,585 21,024 Series D convertible preferred stock 11,690,151 3,896,711 51,952 52,115 Series E convertible preferred stock 37,460,448 12,403,469 80,084 84,140 Total convertible preferred stock 73,108,323 24,229,281 $ 223,125 $ 232,629

Stock-based Compensation (Table

Stock-based Compensation (Tables)	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Total Stock-based Compensation	Total stock-based compensation is as follows: Three months ended September 30, Nine months ended September 30, 2020 2019 2020 2019 (in thousands) Cost of revenue $ 9 $ 3 $ 17 $ 7 Research and development 295 83 550 183 Sales and marketing 344 73 594 126 General and administrative 719 298 1,202 681 Total stock-based compensation $ 1,367 $ 457 $ 2,363 $ 997
Assumptions used in Estimating Grant-Date Fair Value of Stock-based Awards Using Black-Scholes Option Pricing Model	The estimated grant-date fair value of the Company’s stock-based awards was calculated using the Black-Scholes option pricing model, based on the following assumptions: Three months ended September 30, Nine months ended September 30, Valuation assumptions: 2020 2019 2020 2019 Expected volatility 68%-71% 59% 60%-71% 58%-59% Expected term 5.1-7.0 years 6.0-6.1 years 5.1-7.0 years 5.0-10.0 years Risk-free interest rate 0.23%-0.46% 1.46%-1.72% 0.23% - 1.46%-2.51% Dividend yield — — — —
Summary of Activity under the 2010 Plan	Activity under the 2010 Plan is set forth below: Number of shares Weighted average exercise price Weighted average remaining contractual term Aggregate intrinsic value (in years) (in thousands) Balance December 31, 2019 3,474,052 $ 2.93 8.55 $ 16,440 Grants 3,885,943 3.45 Exercises (268,656 ) 1.33 Cancelled/forfeited (329,827 ) 3.72 Balance September 30, 2020 6,761,512 $ 2.53 8.97 $ 21,620 Vested and exercisable at September 30, 2020 1,547,632 $ 1.71 7.51 $ 6,806

Net Income (Loss) Per Share A_2

Net Income (Loss) Per Share Attributable To Common Stockholders (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Summary of Outstanding Potentially Dilutive Common Stock Equivalents Excluded from Calculation of Diluted Net Income (Loss) Per Share	The following outstanding potentially dilutive common stock equivalents have been excluded from the computation of diluted net income (loss) per share for the periods presented due to their anti-dilutive effect: Three months ended September 30, Nine months ended September 30, 2020 2019 2020 2019 Convertible preferred stock 28,196,388 13,710,242 28,196,388 13,710,242 Common stock options issued and outstanding 6,761,512 3,438,285 6,761,512 3,438,285 Convertible preferred stock warrants 137,812 73,913 137,812 73,913 Total 35,095,712 17,222,440 35,095,712 17,222,440
Computation of Basic And Diluted Net Income (Loss) Per Share Attributable to Common Stockholders	The following table sets forth the computation of basic and diluted net income (loss) per share attributable to common stockholders: Three months ended September 30, Nine months ended September 30, 2020 2019 2020 2019 (in thousands, except share and per share amounts) Numerator: Net loss $ (9,726 ) $ (12,157 ) $ (28,056 ) $ (31,139 ) Gain on extinguishment of Series C and Series C-1 convertible preferred stock 9,840 — 9,840 — Undistributed earnings allocated to participating securities (114 ) — — — Net income (loss) attributable to common stockholders, basic and diluted $ — $ (12,157 ) $ (18,216 ) $ (31,139 ) Denominator: Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, basic and diluted 398,895 262,785 315,546 253,701 Net income (loss) per share attributable to common stockholders, basic and diluted $ — $ (46.26 ) $ (57.73 ) $ (122.74 )

Description of Business - Addit

Description of Business - Additional Information (Details) $ / shares in Units, $ in Thousands	Oct. 20, 2020USD ($)$ / sharesshares	Sep. 30, 2020USD ($)	Dec. 31, 2019USD ($)
Description Of Business [Line Items]
Cash and cash equivalents		$ 70,224	$ 13,384
Accumulated deficit		187,259	$ 159,203
IPO, Including Underwriters' Option
Description Of Business [Line Items]
Offering costs incurred		1,300
Subsequent Event | IPO
Description Of Business [Line Items]
Reverse stock split ratio	3
Common Stock | IPO, Including Underwriters' Option
Description Of Business [Line Items]
Net proceeds from issuance of common stock		148,100
Offering costs incurred		$ 1,300
Common Stock | Subsequent Event | IPO
Description Of Business [Line Items]
Issuance of stock | shares	7,851,852
Conversion of outstanding convertible preferred stock into common stock | shares	28,196,388
Conversion of convertible preferred stock warrants into common stock | shares	137,812
Common Stock | Subsequent Event | Underwriters' Option
Description Of Business [Line Items]
Issuance of stock | shares	1,177,777
Common Stock | Subsequent Event | IPO, Including Underwriters' Option
Description Of Business [Line Items]
Issuance of stock | shares	9,029,629
Offering price per share | $ / shares	$ 18
Net proceeds from issuance of common stock	$ 148,100
Underwriters’ discounts and commissions	11,400
Estimated offering costs	$ 3,100

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Thousands	1 Months Ended	9 Months Ended
	Mar. 31, 2020	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
Summary Of Significant Accounting Policies [Line Items]
Allowance for doubtful accounts receivable		$ 2,300		$ 200
Operating right-of-use assets		1,369	$ 2,200
Operating lease liabilities		$ 1,509	2,400
Deferred rent liability derecognized			$ 200
Lease, practical expedients, package		true
ASU 2016-02
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adoption date		Jan. 1, 2020
Change in accounting principle, accounting standards update, adopted		true
Change in accounting principle, accounting standards update, early adoption		true
ASU 2018-13
Summary Of Significant Accounting Policies [Line Items]
Change in accounting principle, accounting standards update, adoption date		Jan. 1, 2020
Change in accounting principle, accounting standards update, adopted		true
Change in accounting principle, accounting standards update, immaterial effect		true
General and Administrative Expenses
Summary Of Significant Accounting Policies [Line Items]
Deferred offering costs expensed	$ 1,600
Other Assets
Summary Of Significant Accounting Policies [Line Items]
Deferred offering costs		$ 1,300		$ 1,200

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - Fair Value on Recurring Basis - Convertible Preferred Stock Warrant Liability - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Liabilities:
Liabilities	$ 544	$ 396
Level 3
Liabilities:
Liabilities	$ 544	$ 396

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Change in Estimated Fair Value of Convertible Preferred Stock Warrant Liability (Details) - Convertible Preferred Stock Warrant Liability - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance	$ 396	$ 81
Fair value of convertible preferred stock warrants issued in connection with debt financing	270	41
Change in fair value of warrant liability	(122)	84
Balance	$ 544	$ 206

Fair Value Measurements - Sum_3

Fair Value Measurements - Summary of Fair Value of Convertible Preferred Stock Warrants Determined Using Following Assumptions (Details) - Convertible Preferred Stock Warrant Liability	Sep. 30, 2020	Dec. 31, 2019
Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Expected term	2 years 2 months 12 days	1 year
Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Expected term	9 years 10 months 24 days	8 years 7 months 6 days
Expected Volatility | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.70	0.43
Expected Volatility | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.71	0.67
Risk-Free Interest Rate | Minimum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.0014	0.0159
Risk-Free Interest Rate | Maximum
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Warrants measurement input	0.0069	0.0188

Fair Value Measurements - Sum_4

Fair Value Measurements - Summary of Change in Estimated Fair Value of Derivative Liability (Details) - Embedded Derivatives $ in Thousands	9 Months Ended
	Sep. 30, 2020USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Balance — December 31, 2019	$ 0
Initial fair value of derivative liability	2,879
Change in fair value of derivative liability	206
Extinguishment of derivative liability	(3,085)
Balance — September 30, 2020	$ 0

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Inventories (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Inventory Disclosure [Abstract]
Raw materials	$ 1,163	$ 1,115
Finished goods	2,126	1,765
Total inventories	$ 3,289	$ 2,880

Balance Sheet Components - Su_2

Balance Sheet Components - Summary of Property And Equipment, Net (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 11,334	$ 8,119
Less accumulated depreciation and amortization	(4,388)	(2,719)
Total property and equipment, net	6,946	5,400
Tools and Lab Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	3,630	2,885
Capitalized Software
Property Plant And Equipment [Line Items]
Total property and equipment, gross	5,753	3,148
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Total property and equipment, gross	906	906
Leasehold Improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	757	757
Computer and Equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 288	$ 423

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Property Plant And Equipment [Abstract]
Depreciation and amortization expense	$ 700	$ 400	$ 1,805	$ 1,011
Amortization of capitalized software costs	$ 200	$ 100	$ 600	$ 200

Balance Sheet Components - Su_3

Balance Sheet Components - Summary of Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Allowance for sales returns	$ 3,123	$ 3,759
Accrued compensation	4,428	2,739
Accrued vendor costs	438	2,776
Refunds due to customers	1,050	215
Accrued warranty reserve	1,770	450
Total accrued expenses	$ 10,809	$ 9,939

Balance Sheet Components - Su_4

Balance Sheet Components - Summary of Accrued Warranty Reserve (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Accrued warranty reserve, beginning balance	$ 450	$ 53
Charged to cost of revenue	2,318	1,589
Utilization of accrued warranty reserve	(998)	(1,192)
Accrued warranty reserve, ending balance	$ 1,770	$ 450

Commitment and Contingencies -

Commitment and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Jan. 01, 2020
Commitments And Contingencies Disclosure [Abstract]
Operating lease right-of-use assets	$ 1,369	$ 1,369	$ 2,200
Operating lease liabilities	$ 1,509	$ 1,509	$ 2,400
ROU asset and operating lease liability, weighted-average incremental borrowing rate		7.10%
Operating lease, weighted-average remaining lease term	1 year 3 months 18 days	1 year 3 months 18 days
Operating lease costs	$ 300	$ 900
Cash paid for operating lease liabilities	$ 300	$ 1,000

Commitment and Contingencies _2

Commitment and Contingencies - Schedule of Undiscounted Future Minimum Lease Payments Due under Non-cancelable Operating Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Jan. 01, 2020
Commitments And Contingencies Disclosure [Abstract]
Remainder of 2020	$ 335
2021	1,074
2022	167
Total minimum future lease payments	1,576
Present value adjustment for minimum lease commitments	(67)
Operating lease liabilities	$ 1,509	$ 2,400

Commitment and Contingencies _3

Commitment and Contingencies - Schedule of Undiscounted Future Minimum Lease Payments Due under Non-cancelable Operating Leases - Prior Guidance (Details) $ in Thousands	Dec. 31, 2019USD ($)
Commitments And Contingencies Disclosure [Abstract]
2020	$ 1,349
2021	1,092
2022	167
Total minimum future lease payments	$ 2,608

Debt Obligations - Additional I

Debt Obligations - Additional Information (Details) - USD ($)	1 Months Ended											3 Months Ended		9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Jul. 31, 2020	May 31, 2020	Mar. 31, 2020	Jun. 30, 2019	Jan. 31, 2019	Dec. 31, 2018	Nov. 30, 2018	Oct. 31, 2018	Jun. 30, 2018	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	May 03, 2020	Apr. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Proceeds from debt financing														$ 15,000,000	$ 5,000,000
Debt, final payment as percentage of original aggregate principal amount	6.00%
Interest expense												$ 279,000	$ 218,000	1,422,000	492,000
Loss on extinguishment of debt												$ 1,627,000		$ 1,627,000
Series C Convertible Preferred Stock
Debt Instrument [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share	$ 9.0201											$ 9.0201		$ 9.0201
Series E Convertible Preferred Stock
Debt Instrument [Line Items]
Debt conversion, convertible to preferred stock, value												$ 12,818,000
Conversion of convertible securities in to stock												1,889,548
Percentage of share price paid by investor in preferred stock financing			80.00%
Share price per share paid by investor in preferred stock financing			$ 6.7836
2018 Loan Agreement
Debt Instrument [Line Items]
Aggregate principal amount											$ 12,500,000
Proceeds from debt financing								$ 1,000,000	$ 1,000,000	$ 5,000,000
Maturity period											2022-06
Term loans, interest rate terms														The term loans under the 2018 Loan Agreement mature in June 2022, with interest-only monthly payments for a specified period of time. Interest on the term loans accrued at a per annum rate equal to the Wall Street Journal prime rate minus 1.0% with a floor of 0.0%.
2018 Loan Agreement | Wall Street Journal Prime Rate
Debt Instrument [Line Items]
Term loans, interest rate											1.00%
Term loans, floor rate											0.00%
Amendments 2018 Loan Agreement
Debt Instrument [Line Items]
Aggregate principal amount	$ 20,000,000											$ 20,000,000		$ 20,000,000
Proceeds from debt financing	$ 15,000,000					$ 5,000,000
Maturity period	2024-09			2022-06			2020-01
Term loans, interest rate terms														The term loan under the Third Amendment matures in September 2024 with interest-only monthly payments until January 2022, which was extended to July 2022 upon the completion of the Company’s IPO in October 2020. The term loan accrues interest at a per annum rate equal to the Wall Street Journal prime rate plus 1.0% (4.25% as of September 30, 2020) and includes a final payment fee equal to 6.25% of the original aggregate principal amount.
Principal value																		$ 12,000,000
Repayments on outstanding debt	$ 10,200,000
Final payment fee	9,500,000
Payments on existing term loan	$ 700,000
Debt, final payment as percentage of original aggregate principal amount	6.25%
Accrued final payment fee	$ 15,000,000											$ 15,000,000		$ 15,000,000
Interest expense														$ 500,000	$ 500,000
Effective interest rate	8.06%											8.06%		8.06%
Amendments 2018 Loan Agreement | Series C Convertible Preferred Stock | Silicon Valley Bank
Debt Instrument [Line Items]
Warrants issued to purchase shares of convertible preferred stock						14,999					30,173
Amendments 2018 Loan Agreement | Series E Convertible Preferred Stock | Silicon Valley Bank
Debt Instrument [Line Items]
Warrants issued to purchase shares of convertible preferred stock	53,487											53,487		53,487
Class of warrant additional shares authorized to purchase	17,829											17,829		17,829
Amendments 2018 Loan Agreement | Wall Street Journal Prime Rate
Debt Instrument [Line Items]
Term loans, interest rate	1.00%													4.25%
Promissory Note | CARES Act | PPP Loan
Debt Instrument [Line Items]
Aggregate principal amount																$ 4,600,000
Repayments on outstanding debt		$ 4,600,000
Interest expense												$ 100,000		$ 100,000
Interest rate																1.00%
Debt instrument, frequency of periodic payment														Monthly principal and interest payments
2020 Notes
Debt Instrument [Line Items]
Aggregate principal amount					$ 8,900,000												$ 1,200,000
Maturity period					2021-03
Interest expense														$ 900,000
Interest rate					6.00%
Debt discount					$ 2,900,000
2020 Notes | Other Income (Expense)
Debt Instrument [Line Items]
Loss on extinguishment of debt			$ 1,600,000
2020 Notes | Preferred Stock
Debt Instrument [Line Items]
Debt instrument convert, threshold percentage of equity financing price per share					80.00%
2020 Notes | Common Stock
Debt Instrument [Line Items]
Debt instrument convert, threshold percentage of equity financing price per share					90.00%
2020 Notes | Minimum
Debt Instrument [Line Items]
Potential proceeds from sale of equity					$ 15,000,000
2020 Notes | Series E Convertible Preferred Stock
Debt Instrument [Line Items]
Debt conversion, convertible to preferred stock, value			10,100,000											$ 10,300,000
Debt conversion, accrued interest convertible to preferred stock, value			$ 200,000
Conversion of convertible securities in to stock			1,889,548											1,889,548
Debt conversion, convertible to preferred stock, conversion price per share			$ 5.427

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	2 Months Ended	3 Months Ended		9 Months Ended
	Jul. 31, 2020	Aug. 31, 2020	Sep. 30, 2020	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Oct. 20, 2020	Dec. 31, 2019
Temporary Equity [Line Items]
Proceeds from convertible preferred stock issuance, net of issuance costs					$ 67,867	$ 865
Net carrying value			$ 223,125		223,125			$ 152,880
Common Stock | Subsequent Event
Temporary Equity [Line Items]
Convertible preferred stock converted into common stock							28,196,388
Series E Convertible Preferred Stock
Temporary Equity [Line Items]
Issuance of stock		10,513,921	10,513,921
Shares issued price per share		$ 6.7836
Proceeds from convertible preferred stock issuance, net of issuance costs		$ 67,300
Debt conversion, convertible to preferred stock, value			$ 12,818
Conversion of convertible securities in to stock			1,889,548
Net carrying value			$ 80,084		80,084
Series E Convertible Preferred Stock | 2020 Notes
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, value	$ 10,100				$ 10,300
Conversion of convertible securities in to stock	1,889,548				1,889,548
Debt conversion, convertible to preferred stock, conversion price per share	$ 5.427
Series A convertible preferred stock
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 27.87		$ 27.87
Net carrying value			$ 16,130		$ 16,130
Series A convertible preferred stock | Anti-dilution Adjustments Effect
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 19.599		$ 19.599
Series B convertible preferred stock
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 60.60		$ 60.60
Net carrying value			$ 2,229		$ 2,229
Series B convertible preferred stock | Anti-dilution Adjustments Effect
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 39.6303		$ 39.6303
Series B-1 convertible preferred stock
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 9.0201		$ 9.0201
Net carrying value			$ 22,871		$ 22,871
Series B-1 convertible preferred stock | Anti-dilution Adjustments Effect
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 8.0625		$ 8.0625
Series C Convertible Preferred Stock
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 9.0201		$ 9.0201
Net carrying value			$ 29,274		$ 29,274
Series C Convertible Preferred Stock | Anti-dilution Adjustments Effect
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 8.0625		$ 8.0625
Series C-1 convertible preferred stock
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 7.2162		$ 7.2162
Net carrying value			$ 20,585		$ 20,585
Series C-1 convertible preferred stock | Anti-dilution Adjustments Effect
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 6.9585		$ 6.9585
Series D Convertible Preferred Stock
Temporary Equity [Line Items]
Issuance of stock				64,653
Debt conversion, convertible to preferred stock, conversion price per share			$ 13.374		$ 13.374
Net carrying value			$ 51,952		$ 51,952
Series D Convertible Preferred Stock | Anti-dilution Adjustments Effect
Temporary Equity [Line Items]
Debt conversion, convertible to preferred stock, conversion price per share			$ 10.7271		$ 10.7271
Series C and Series C-1 Convertible Preferred Stock
Temporary Equity [Line Items]
Gain on extinguishment of Series C and Series C-1 convertible preferred stock					$ 9,800
Net carrying value			$ 59,700		59,700
Fair value			$ 49,900		$ 49,900

Convertible Preferred Stock - S

Convertible Preferred Stock - Summary of Convertible Preferred Stock (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Temporary Equity [Line Items]
Shares authorized	73,108,323	36,269,166
Shares issued	24,229,281	11,825,812
Shares outstanding	24,229,281	11,825,812
Net carrying value	$ 223,125	$ 152,880
Aggregate liquidation preference	$ 232,629
Series A convertible preferred stock
Temporary Equity [Line Items]
Shares authorized	1,282,894
Shares issued	423,713
Shares outstanding	423,713
Net carrying value	$ 16,130
Aggregate liquidation preference	$ 16,271
Series B convertible preferred stock
Temporary Equity [Line Items]
Shares authorized	82,972
Shares issued	27,652
Shares outstanding	27,652
Net carrying value	$ 2,229
Aggregate liquidation preference	$ 2,473
Series B-1 convertible preferred stock
Temporary Equity [Line Items]
Shares authorized	2,539,761
Shares issued	838,892
Shares outstanding	838,892
Net carrying value	$ 22,871
Aggregate liquidation preference	$ 23,003
Series C Convertible Preferred Stock
Temporary Equity [Line Items]
Shares authorized	11,311,611
Shares issued	3,725,354
Shares outstanding	3,725,354
Net carrying value	$ 29,274
Aggregate liquidation preference	$ 33,603
Series C-1 convertible preferred stock
Temporary Equity [Line Items]
Shares authorized	8,740,486
Shares issued	2,913,490
Shares outstanding	2,913,490
Net carrying value	$ 20,585
Aggregate liquidation preference	$ 21,024
Series D Convertible Preferred Stock
Temporary Equity [Line Items]
Shares authorized	11,690,151
Shares issued	3,896,711
Shares outstanding	3,896,711
Net carrying value	$ 51,952
Aggregate liquidation preference	$ 52,115
Series E Convertible Preferred Stock
Temporary Equity [Line Items]
Shares authorized	37,460,448
Shares issued	12,403,469
Shares outstanding	12,403,469
Net carrying value	$ 80,084
Aggregate liquidation preference	$ 84,140

Stock-based Compensation - Summ

Stock-based Compensation - Summary of Total Stock-based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 1,367	$ 457	$ 2,363	$ 997
Cost of Revenue
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	9	3	17	7
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	295	83	550	183
Sales and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	344	73	594	126
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total stock-based compensation	$ 719	$ 298	$ 1,202	$ 681

Stock-based Compensation - Addi

Stock-based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2020	Aug. 31, 2020	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options canceled		1,574,243
Options granted		1,574,243
Options granted, exercise price		$ 2.55
Stock-based compensation			$ 1,367	$ 457	$ 2,363	$ 997
Unrecognized stock-based compensation	$ 800		$ 800		$ 800
2010 Equity Incentive Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options canceled					329,827
Options granted					3,885,943
Options granted, exercise price					$ 3.45
Common stock reserved for issuance	7,104,636		7,104,636		7,104,636
Weighted-average grant-date fair value of options granted					$ 3.05	$ 2.75
Unrecognized stock-based compensation related to outstanding unvested stock options	$ 16,300		$ 16,300		$ 16,300
Unrecognized stock-based compensation related to outstanding unvested stock options, period of recognition					3 years 2 months 19 days
Stock Option Repricing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation		$ 1,200	400		$ 400
Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation			$ 300		300
Service-Based and Performance-Based Vesting Conditions
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options granted	212,489	1,129,270
Stock-based compensation					$ 200
Share-based compensation, options grants in period, grant date fair value	$ 700	$ 3,700
Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock options, per share exercise price		$ 2.55

Stock-based Compensation - Assu

Stock-based Compensation - Assumptions used in Estimating Grant-Date Fair Value of Stock-based Awards Using Black-Scholes Option Pricing Model (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Valuation assumptions:
Expected volatility, Minimum	68.00%		60.00%	58.00%
Expected volatility		59.00%
Expected volatility, Maximum	71.00%		71.00%	59.00%
Risk-free interest rate, Minimum	0.23%	1.46%	0.23%	1.46%
Risk-free interest rate, Maximum	0.46%	1.72%	1.20%	2.51%
Minimum
Valuation assumptions:
Expected term	5 years 1 month 6 days	6 years	5 years 1 month 6 days	5 years
Maximum
Valuation assumptions:
Expected term	7 years	6 years 1 month 6 days	7 years	10 years

Stock-based Compensation - Su_2

Stock-based Compensation - Summary of Activity under the 2010 Plan (Details) $ / shares in Units, $ in Thousands	1 Months Ended	9 Months Ended	12 Months Ended
	Aug. 31, 2020$ / sharesshares	Sep. 30, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / sharesshares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Grants	1,574,243
Number of shares, Cancelled/forfeited	(1,574,243)
Weighted average exercise price, Grants | $ / shares	$ 2.55
2010 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares, Balance		3,474,052
Number of shares, Grants		3,885,943
Number of shares, Exercises		(268,656)
Number of shares, Cancelled/forfeited		(329,827)
Number of shares, Balance		6,761,512	3,474,052
Number of shares, Vested and exercisable		1,547,632
Weighted average exercise price, Balance | $ / shares		$ 2.93
Weighted average exercise price, Grants | $ / shares		3.45
Weighted average exercise price, Exercises | $ / shares		1.33
Weighted average exercise price, Cancelled/forfeited | $ / shares		3.72
Weighted average exercise price, Balance | $ / shares		2.53	$ 2.93
Weighted average exercise price, Vested and exercisable | $ / shares		$ 1.71
Weighted average remaining contractual term, Balance		8 years 11 months 19 days	8 years 6 months 18 days
Weighted average remaining contractual term, Vested and exercisable		7 years 6 months 3 days
Aggregate intrinsic value, Balance | $		$ 21,620	$ 16,440
Aggregate intrinsic value, Vested and exercisable | $		$ 6,806

Net Income (Loss) Per Share A_3

Net Income (Loss) Per Share Attributable To Common Stockholders - Summary of Outstanding Potentially Dilutive Common Stock Equivalents Excluded from Calculation of Diluted Net Income (Loss) Per Share (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net income (loss) per share	35,095,712	17,222,440	35,095,712	17,222,440
Common Stock Options Issued and Outstanding
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net income (loss) per share	6,761,512	3,438,285	6,761,512	3,438,285
Convertible Preferred Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net income (loss) per share	137,812	73,913	137,812	73,913
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net income (loss) per share	28,196,388	13,710,242	28,196,388	13,710,242

Net Income (Loss) Per Share A_4

Net Income (Loss) Per Share Attributable To Common Stockholders - Computation of Basic And Diluted Net Income (Loss) Per Share Attributable to Common Stockholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
Numerator:
Net loss and comprehensive loss	$ (9,726)	$ (6,592)	$ (11,738)	$ (12,157)	$ (9,759)	$ (9,223)	$ (28,056)	$ (31,139)
Gain on extinguishment of Series C and Series C-1 convertible preferred stock	9,840						9,840
Undistributed earnings allocated to participating securities	$ (114)
Net income (loss) attributable to common stockholders, basic and diluted				$ (12,157)			$ (18,216)	$ (31,139)
Denominator:
Weighted-average shares used in computing net income (loss) per share attributable to common stockholders, basic and diluted	398,895			262,785			315,546	253,701
Net income (loss) per share attributable to common stockholders, basic and diluted				$ (46.26)			$ (57.73)	$ (122.74)

Subsequent Events - Additional

Subsequent Events - Additional Information (Details) $ / shares in Units, $ in Millions	Oct. 31, 2020shares	Oct. 20, 2020USD ($)$ / sharesshares	Nov. 20, 2020shares	Aug. 31, 2020shares	Sep. 30, 2020USD ($)$ / sharesshares	Oct. 19, 2020$ / sharesshares	Dec. 31, 2019$ / sharesshares
Subsequent Event [Line Items]
Common stock, shares authorized					110,000,000		55,190,000
Common stock, par value | $ / shares					$ 0.0001		$ 0.0001
Options granted				1,574,243
IPO, Including Underwriters' Option
Subsequent Event [Line Items]
Offering costs incurred | $					$ 1.3
IPO, Including Underwriters' Option | Common Stock
Subsequent Event [Line Items]
Net proceeds from issuance of common stock | $					148.1
Offering costs incurred | $					$ 1.3
Subsequent Event | Silicon Valley Bank
Subsequent Event [Line Items]
Conversion of convertible preferred stock warrants into common stock			119,107
Common stock issued for warrants exercised			93,440
Subsequent Event | 2020 Equity Incentive Plan
Subsequent Event [Line Items]
Shares available for grants	0
Common stock reserved for issuance	4,687,685
Subsequent Event | 2020 Employee Stock Purchase Plan
Subsequent Event [Line Items]
Common stock reserved for issuance	726,773
Subsequent Event | IPO
Subsequent Event [Line Items]
Reverse stock split, description		In October 2020, the Company’s board of directors approved an amended and restated certificate of incorporation to effect a reverse split of shares of the Company’s common stock and convertible preferred stock on a 3-for-1 basis, which was effective as of October 8, 2020. The number of authorized shares and the par values of the common stock and convertible preferred stock were not adjusted as a result of the Reverse Stock Split.
Reverse stock split ratio		3
Cumulative stock-based compensation | $		$ 0.1
Common stock, shares authorized						300,000,000
Common stock, par value | $ / shares						$ 0.0001
Preferred stock, shares authorized						5,000,000
Preferred stock, par value | $ / shares						$ 0.0001
Subsequent Event | IPO | 2020 Equity Incentive Plan
Subsequent Event [Line Items]
Options granted	114,211
Subsequent Event | IPO | Common Stock
Subsequent Event [Line Items]
Stock issued and sold		7,851,852
Conversion of outstanding convertible preferred stock into common stock		28,196,388
Conversion of convertible preferred stock warrants into common stock		137,812
Subsequent Event | Underwriters' Option | Common Stock
Subsequent Event [Line Items]
Stock issued and sold		1,177,777
Subsequent Event | IPO, Including Underwriters' Option | Common Stock
Subsequent Event [Line Items]
Stock issued and sold		9,029,629
Stock issued and sold, price per share | $ / shares		$ 18
Net proceeds from issuance of common stock | $		$ 148.1
Underwriters’ discounts and commissions | $		11.4
Estimated offering costs | $		$ 3.1