Adaptive Biotechnologies (ADPT) 10-Q 12 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Oct. 31, 2019
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Trading Symbol	ADPT
Entity Registrant Name	ADAPTIVE BIOTECHNOLOGIES CORPORATION
Entity Central Index Key	0001478320
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
Title of 12(b) Security	Common stock, par value $0.0001 per share
Security Exchange Name	NASDAQ
Entity Common Stock, Shares Outstanding		124,339,058
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Interactive Data Current	Yes
Entity File Number	001-38957
Entity Tax Identification Number	27-0907024
Entity Address, Address Line One	1551 Eastlake Avenue East
Entity Address, Address Line Two	Suite 200
Entity Address, City or Town	Seattle
Entity Address, State or Province	WA
Entity Address, Postal Zip Code	98102
City Area Code	(206)
Local Phone Number	659-0067
Document Quarterly Report	true
Document Transition Report	false
Entity Incorporation, State or Country Code	WA

Condensed Balance Sheets

Condensed Balance Sheets - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 74,941,000	$ 55,030,000
Short-term marketable securities	498,487,000	109,988,000
Accounts receivable, net	9,257,000	4,807,000
Inventory	8,667,000	7,838,000
Prepaid expenses and other current assets	10,004,000	3,055,000
Total current assets	601,356,000	180,718,000
Long-term assets
Property and equipment, net	46,542,000	19,125,000
Long-term marketable securities	135,306,000
Restricted cash	2,138,000	61,000
Intangible assets, net	12,356,000	13,626,000
Goodwill	118,972,000	118,972,000
Other assets	722,000	186,000
Total assets	917,392,000	332,688,000
Current liabilities
Accounts payable	2,421,000	1,793,000
Accrued liabilities	3,381,000	2,562,000
Accrued compensation and benefits	5,982,000	4,641,000
Current portion of deferred rent	324,000	1,109,000
Current deferred revenue	61,269,000	12,695,000
Total current liabilities	73,377,000	22,800,000
Long-term liabilities
Convertible preferred stock warrant liability		336,000
Deferred rent liability, less current portion	6,258,000	6,102,000
Financing obligation	23,449,000
Deferred revenue, less current portion	228,339,000	704,000
Other long-term liabilities	44,000
Total liabilities	331,467,000	29,942,000
Commitments and contingencies (Note 8)
Convertible preferred stock: $0.0001 par value, no and 93,762,517 shares authorized at September 30, 2019 and December 31, 2018, respectively; no and 92,790,094 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively; aggregate liquidation preference of $0 and $572,866 at September 30, 2019 and December 31, 2018, respectively		560,858,000
Shareholders’ equity (deficit)
Preferred stock: $0.0001 par value, 10,000,000 and no shares authorized at September 30, 2019 and December 31, 2018, respectively; no shares issued and outstanding at September 30, 2019 and December 31, 2018
Common stock: $0.0001 par value, 340,000,000 and 131,000,000 shares authorized at September 30, 2019 and December 31, 2018, respectively; 124,316,080 and 12,841,536 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively	12,000	1,000
Additional paid-in capital	930,208,000	37,902,000
Accumulated other comprehensive gain (loss)	572,000	(107,000)
Accumulated deficit	(344,867,000)	(295,908,000)
Total shareholders’ equity (deficit)	585,925,000	(258,112,000)
Total liabilities, convertible preferred stock and shareholders’ equity (deficit)	$ 917,392,000	$ 332,688,000

Condensed Balance Sheets (Paren

Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Convertible preferred stock par value	$ 0.0001	$ 0.0001
Convertible preferred stock authorized	0	93,762,517
Convertible preferred stock issued	0	92,790,094
Convertible preferred stock outstanding	0	92,790,094
Convertible preferred stock aggregate liquidation preference	$ 0	$ 572,866
Preferred stock par value	$ 0.0001	$ 0.0001
Preferred stock authorized	10,000,000	0
Preferred stock issued	0	0
Preferred stock outstanding	0	0
Common stock par value	$ 0.0001	$ 0.0001
Common stock authorized	340,000,000	131,000,000
Common stock issued	124,316,080	12,841,536
Common stock outstanding	124,316,080	12,841,536

Condensed Statements of Operati

Condensed Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue
Total revenue	$ 26,058	$ 17,188	$ 60,862	$ 38,471
Operating expenses
Cost of revenue	5,601	5,360	16,323	14,393
Research and development	20,506	9,783	49,516	28,090
Sales and marketing	9,099	6,039	25,813	16,415
General and administrative	8,477	4,739	22,143	13,914
Amortization of intangible assets	428	428	1,270	1,271
Total operating expenses	44,111	26,349	115,065	74,083
Loss from operations	(18,053)	(9,161)	(54,203)	(35,612)
Interest and other income, net	4,103	869	6,208	2,436
Net loss	(13,950)	(8,292)	(47,995)	(33,176)
Fair value adjustment to Series E-1 convertible preferred stock options		(4)	(964)	(2)
Net loss attributable to common shareholders	$ (13,950)	$ (8,296)	$ (48,959)	$ (33,178)
Net loss per share attributable to common shareholders, basic and diluted	$ (0.11)	$ (0.66)	$ (0.97)	$ (2.67)
Weighted-average shares used in computing net loss per share attributable to common shareholders, basic and diluted	124,285,686	12,620,010	50,552,389	12,430,535
Sequencing Revenue
Revenue
Total revenue	$ 11,683	$ 8,463	$ 29,631	$ 22,524
Development Revenue
Revenue
Total revenue	$ 14,375	$ 8,725	$ 31,231	$ 15,947

Condensed Statements of Compreh

Condensed Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Financial Position [Abstract]
Net loss	$ (13,950)	$ (8,292)	$ (47,995)	$ (33,176)
Change in unrealized gain (loss) on investments	190	39	679	(35)
Comprehensive loss	$ (13,760)	$ (8,253)	$ (47,316)	$ (33,211)

Condensed Statements of Convert

Condensed Statements of Convertible Preferred Stock and Shareholders' (Deficit) Equity - USD ($) $ in Thousands	Total	Convertible Preferred Stock	Common Stock	Additional Paid In Capital	Accumulated Other Comprehensive (Loss) Gain	Accumulated Deficit
Beginning Balance at Dec. 31, 2017	$ (224,616)		$ 1	$ 24,972	$ (166)	$ (249,423)
Beginning Balance, Shares at Dec. 31, 2017			12,208,731
Convertible preferred stock, Beginning Balance at Dec. 31, 2017		$ 561,333
Convertible preferred stock, Beginning Balance, Shares at Dec. 31, 2017		92,656,029
Adjustments to accumulated deficit for adoption of guidance on accounting for share-based payment transactions (unaudited)				140		(140)
Issuance of common stock for cash upon exercise of stock options (unaudited)	885			885
Issuance of common stock for cash upon exercise of stock options (unaudited), Shares			512,696
Issuance of Series E-1 convertible preferred stock for cash uponexercise of Series E-1 convertible preferred stock options at fair value (unaudited)		$ 100
Issuance of Series E-1 convertible preferred stock for cash upon exercise of Series E-1 convertible preferred stock options at fair value (unaudited), Shares		134,065
Vested Series E-1 convertible preferred stock option forfeitures (unaudited)	767			476		291
Vested Series E-1 convertible preferred stock option forfeitures (unaudited)		$ (767)
Series E-1 convertible preferred stock option share-based compensation (unaudited)	3			3
Adjustment to redemption value for vested Series E-1 convertiblepreferred stock options (unaudited)	(3)			(3)
Adjustment to redemption value for vested Series E-1 convertible preferred stock options (unaudited)		3
Change in redemption value for vested Series E-1 convertible preferred stock options (unaudited)	(2)					(2)
Change in redemption value for vested Series E-1 convertible preferred stock options (unaudited)		2
Common stock option share-based compensation (unaudited)	8,100			8,100
Other comprehensive income (unaudited)	(35)				(35)
Net loss	(33,176)					(33,176)
Convertible preferred stock, Ending Balance at Sep. 30, 2018		$ 560,671
Convertible preferred stock, Ending Balance, Shares at Sep. 30, 2018		92,790,094
Ending Balance at Sep. 30, 2018	(248,077)		$ 1	34,573	(201)	(282,450)
Ending Balance, Shares at Sep. 30, 2018			12,721,427
Beginning Balance at Jun. 30, 2018	(242,435)		$ 1	31,958	(240)	(274,154)
Beginning Balance, Shares at Jun. 30, 2018			12,546,844
Convertible preferred stock, Beginning Balance at Jun. 30, 2018		$ 560,667
Convertible preferred stock, Beginning Balance, Shares at Jun. 30, 2018		92,790,094
Issuance of common stock for cash upon exercise of stock options (unaudited)	62			62
Issuance of common stock for cash upon exercise of stock options (unaudited), Shares			174,583
Change in redemption value for vested Series E-1 convertible preferred stock options (unaudited)	(4)					(4)
Change in redemption value for vested Series E-1 convertible preferred stock options (unaudited)		$ 4
Common stock option share-based compensation (unaudited)	2,553			2,553
Other comprehensive income (unaudited)	39				39
Net loss	(8,292)					(8,292)
Convertible preferred stock, Ending Balance at Sep. 30, 2018		$ 560,671
Convertible preferred stock, Ending Balance, Shares at Sep. 30, 2018		92,790,094
Ending Balance at Sep. 30, 2018	(248,077)		$ 1	34,573	(201)	(282,450)
Ending Balance, Shares at Sep. 30, 2018			12,721,427
Beginning Balance at Dec. 31, 2018	(258,112)		$ 1	37,902	(107)	(295,908)
Beginning Balance, Shares at Dec. 31, 2018			12,841,536
Convertible preferred stock, Beginning Balance at Dec. 31, 2018	$ 560,858	$ 560,858
Convertible preferred stock, Beginning Balance, Shares at Dec. 31, 2018	92,790,094	92,790,094
Proceeds from initial public offering, net of underwriters' discounts and commissions (unaudited)	$ 320,850		$ 2	320,848
Proceeds from initial public offering, net of underwriters' discounts and commissions (unaudited), Shares			17,250,000
Initial public offering costs (unaudited)	(4,986)			(4,986)
Conversion of convertible preferred stock to common stock (unaudited)	561,931	$ (561,931)	$ 9	561,922
Conversion of convertible preferred stock to common stock (unaudited), Shares		(93,039,737)	93,039,737
Conversion of convertible preferred stock warrant to common stock warrant (unaudited)	2,602			2,602
Issuance of common stock upon exercise of common stock warrants (unaudited)	9			9
Issuance of common stock upon exercise of common stock warrants (unaudited), Shares			54,792
Issuance of common stock for cash upon exercise of stock options (unaudited)	$ 2,198			2,198
Issuance of common stock for cash upon exercise of stock options (unaudited), Shares	1,379,658		1,130,015
Issuance of Series E-1 convertible preferred stock for cash uponexercise of Series E-1 convertible preferred stock options at fair value (unaudited)		$ 109
Issuance of Series E-1 convertible preferred stock for cash upon exercise of Series E-1 convertible preferred stock options at fair value (unaudited), Shares		249,643
Change in redemption value for vested Series E-1 convertible preferred stock options (unaudited)	$ (964)					(964)
Change in redemption value for vested Series E-1 convertible preferred stock options (unaudited)		$ 964
Common stock option and restricted stock unit share-based compensation (unaudited)	9,713			9,713
Other comprehensive income (unaudited)	679				679
Net loss	$ (47,995)					(47,995)
Convertible preferred stock, Ending Balance, Shares at Sep. 30, 2019	0	93,039,737
Ending Balance at Sep. 30, 2019	$ 585,925		$ 12	930,208	572	(344,867)
Ending Balance, Shares at Sep. 30, 2019			124,316,080
Beginning Balance at Jun. 30, 2019	(284,374)		$ 1	46,160	382	(330,917)
Beginning Balance, Shares at Jun. 30, 2019			13,725,381
Convertible preferred stock, Beginning Balance at Jun. 30, 2019		$ 561,931
Convertible preferred stock, Beginning Balance, Shares at Jun. 30, 2019		93,039,737
Proceeds from initial public offering, net of underwriters' discounts and commissions (unaudited)	320,850		$ 2	320,848
Proceeds from initial public offering, net of underwriters' discounts and commissions (unaudited), Shares			17,250,000
Initial public offering costs (unaudited)	(4,986)			(4,986)
Conversion of convertible preferred stock to common stock (unaudited)	561,931	$ (561,931)	$ 9	561,922
Conversion of convertible preferred stock to common stock (unaudited), Shares		(93,039,737)	93,039,737
Conversion of convertible preferred stock warrant to common stock warrant (unaudited)	2,602			2,602
Issuance of common stock upon exercise of common stock warrants (unaudited)	9			9
Issuance of common stock upon exercise of common stock warrants (unaudited), Shares			54,792
Issuance of common stock for cash upon exercise of stock options (unaudited)	318			318
Issuance of common stock for cash upon exercise of stock options (unaudited), Shares			246,170
Common stock option and restricted stock unit share-based compensation (unaudited)	3,335			3,335
Other comprehensive income (unaudited)	190				190
Net loss	$ (13,950)					(13,950)
Convertible preferred stock, Ending Balance, Shares at Sep. 30, 2019	0	93,039,737
Ending Balance at Sep. 30, 2019	$ 585,925		$ 12	$ 930,208	$ 572	$ (344,867)
Ending Balance, Shares at Sep. 30, 2019			124,316,080

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities
Net loss	$ (47,995)	$ (33,176)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation expense	4,446	3,136
Share-based compensation expense	9,713	8,103
Intangible assets amortization	1,270	1,271
Investment amortization	(3,533)	(824)
Gain on equipment disposals	(72)	(45)
Fair value adjustment of convertible preferred stock warrant	2,266
Other	(8)	4
Changes in operating assets and liabilities:
Accounts receivable, net	(4,398)	(6,787)
Inventory	(829)	(2,313)
Prepaid expenses and other current assets	(6,840)	(916)
Accounts payable and accrued liabilities	3,131	1,729
Deferred rent	(628)	(427)
Deferred revenue	276,209	3,602
Other	(537)	(206)
Net cash provided by (used in) operating activities	232,195	(26,849)
Investing activities
Purchases of property and equipment	(8,784)	(3,804)
Proceeds from sales of equipment		19
Purchases of marketable securities	(772,093)	(137,124)
Proceeds from maturities of marketable securities	252,500	114,016
Net cash used in investing activities	(528,377)	(26,893)
Financing activities
Proceeds from exercise of stock options	2,307	985
Proceeds from initial public offering, net of underwriting discounts and commissions	320,850
Payment of deferred initial public offering costs	(4,986)
Proceeds from issuance of common stock upon the exercise of a common stock warrant	9
Other	(10)	(15)
Net cash provided by financing activities	318,170	970
Net increase (decrease) in cash, cash equivalents and restricted cash	21,988	(52,772)
Cash, cash equivalents and restricted cash at beginning of year	55,091	85,366
Cash, cash equivalents and restricted cash at end of period	77,079	32,594
Noncash investing and financing activities
Purchases of equipment included in accounts payable and accrued liabilities	498	$ 197
Conversion of convertible preferred stock to common stock upon closing of initial public offering	561,931
Conversion of convertible preferred stock warrant to common stock warrant upon closing of initial public offering	$ 2,602

Organization and Description of

Organization and Description of Business	9 Months Ended
	Sep. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization and Description of Business	1. Organization Adaptive Biotechnologies Corporation (“we,” “us” or “our”) is a commercial-stage company advancing the field of immune-driven medicine by harnessing the inherent biology of the adaptive immune system to transform the diagnosis and treatment of disease. We believe the adaptive immune system is nature’s most finely tuned diagnostic and therapeutic for most diseases, but the inability to decode it has prevented the medical community from fully leveraging its capabilities. Our immune medicine platform is the foundation for our expanding suite of products and services. The cornerstone of our immune medicine platform and core immunosequencing product, immunoSEQ, serves as our underlying research and development engine and generates revenue from academic and biopharmaceutical customers. Our first clinical diagnostic product, clonoSEQ, is the first test authorized by the Food and Drug Administration (“FDA”) for the detection and monitoring of minimal residual disease (“MRD”) in patients with select blood cancers. We were incorporated in the State of Washington on September 8, 2009 under the name Adaptive TCR Corporation. On December 21, 2011, we changed our name to Adaptive Biotechnologies Corporation. We are headquartered in Seattle, Washington. Initial Public Offering Our registration statement on Form S-1 related to our initial public offering (“IPO”) was declared effective on June 26, 2019, and our common stock began trading on the Nasdaq Global Select Market on June 27, 2019. On July 1, 2019, we completed our IPO in which we issued and sold 17,250,000 shares of common stock, including shares issued upon the exercise in full of the underwriters’ over-allotment option, at a public offering price of $20.00 per share. We received $315.9 million in net proceeds, after deducting underwriting discounts and commissions of $24.1 million and offering expenses of $5.0 million. Immediately prior to the completion of our IPO on July 1, 2019, 93,039,737 shares of convertible preferred stock then outstanding converted into an equivalent number of shares of common stock. On July 1, 2019, in connection with the closing of our IPO, our amended and restated articles of incorporation, as filed with the Secretary of State of the State of Washington, and our amended and restated bylaws became effective. Also on July 1, 2019, an initial reserve of 15,519,170 shares under our new 2019 Equity Incentive Plan (“2019 Plan”) became effective.

Significant Accounting Policies

Significant Accounting Policies	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Significant Accounting Policies	2. Significant Accounting Policies Basis The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and the related disclosures at the date of the financial statements, as well as the reported amounts of revenues and expenses during the periods presented. We base our estimates on historical experience and other relevant assumptions that we believe to be reasonable under the circumstances. Estimates are used in several areas including, but not limited to, estimates of progress to date for certain performance obligations and the transaction price for certain contracts with customers, share-based compensation, including the fair value of stock, the provision for income taxes, including related reserves, and goodwill, among others. These estimates generally involve complex issues and require judgments, involve the analysis of historical results and prediction of future trends, can require extended periods of time to resolve and are subject to change from period to period. Actual results may differ materially from management’s estimates. Unaudited Interim Condensed Financial Statements In our opinion, the accompanying unaudited condensed financial statements have been prepared in accordance with GAAP for interim financial information. These unaudited condensed financial statements include all adjustments necessary to fairly state the financial position and the results of our operations and cash flows for interim periods in accordance with GAAP. Interim-period results are not necessarily indicative of results of operations or cash flows for a full year or any subsequent interim period. The accompanying unaudited condensed financial statements should be read in conjunction with our audited financial statements and notes included in our prospectus dated June 26, 2019 filed with the Securities and Exchange Commission (“SEC”) on June 27, 2019 in connection with our IPO (“Prospectus”). Reclassifications In the accompanying audited condensed balance sheet, certain prior year amounts have been reclassified to conform to the current period presentation. Specifically, “restricted cash” and “other assets” were previously included together in the restricted cash and other assets line item and are now separately stated. There was no change to total assets as a result of the reclassification. Restricted Cash We are required to maintain certain balances under lease arrangements for our property and facilities leases. We had restricted cash of $2.1 million and $0.1 million as of September 30, 2019 and December 31, 2018, respectively. Concentrations We are subject to a concentration of risk from a limited number of suppliers, or in some cases, single suppliers for some of our laboratory instruments and materials. This risk is managed by targeting a quantity of surplus stock. Cash, cash equivalents and marketable securities are financial instruments that potentially subject us to concentrations of credit risk. We invest in money market funds, U.S. government debt securities, U.S. government agency securities, commercial paper and corporate bonds with high-quality accredited financial institutions. Significant customers are those which represent more than 10% of our total revenue or accounts receivable, net balances at each respective balance sheet date. Revenue from these customers reflects their purchase of our products and services and our collaboration efforts with Genentech. For each significant customer, revenue as a percentage of total revenue for the periods presented and accounts receivable, net as a percentage of total accounts receivable, net as of the periods presented were as follows: Revenue Accounts Receivable, Net Three Months Ended September 30, Nine Months Ended September 30, September 30, December 31, 2019 2018 2019 2018 2019 2018 (unaudited) (unaudited) Customer A 16.0% 15.7% 11.8% 21.6% 39.6% *% Customer B 10.7 * * * * 15.1 Customer C * 35.0 * 19.1 * 13.2 Genentech, Inc. 43.9 * 43.7 * * * * less than 10% Leases Operating Lease Arrangements We have operating lease agreements for the laboratory and office facilities that we occupy. Rent expense is recognized on a straight-line basis over the term of the lease. Incentives granted under our facility leases, including rent holidays, are capitalized and are recognized as adjustments to rental expense on a straight-line basis over the term of the lease. Lease Financing Arrangements Due to our significant involvement during the construction process of a leased building, we qualify as the deemed owner of the building under build-to-suit lease accounting guidance. The cost of the related building is recorded in property and equipment, net and the offsetting lease financing obligation is recorded as a long-term financing obligation on our unaudited condensed balance sheet. As of September 30, 2019, $23.4 million of building costs have been recorded in property and equipment, net. Revenue We recognize revenue in accordance with Accounting Standards Codification (“ASC”) Topic 606 (“ASC 606”), Revenue from Contracts with Customers Overview Our revenue is generated from immunosequencing (“sequencing”) products and services (“sequencing revenue”) and from regulatory or development support services leveraging our immune medicine platform (“development revenue”). When revenue generating contracts have elements of both sequencing revenue and development revenue, we allocate revenue based on the nature of the performance obligation and the allocated transaction price. Sequencing Revenue Sequencing revenue reflects the amounts generated from providing sequencing services and testing through our immunoSEQ and clonoSEQ products and services to our research and clinical customers, respectively. For research customers, contracts typically include an amount billed in advance of services (“upfront”), and subsequent billings as sample results are delivered to the customer. Upfront amounts received are recorded as deferred revenue, which we recognize as revenue upon satisfaction of performance obligations. We have identified two typical performance obligations under the terms of our research service contracts: sequencing services and related data analysis. We recognize revenue for both identified performance obligations as sample results are delivered to the customer. For other research customers who choose to purchase a research use only kit, the kits are sold on a price per kit basis with amounts payable upon delivery of the kit. Payments received are recorded as deferred revenue. For these customers, we have identified one performance obligation: the delivery of sample results. We recognize revenue as the results are delivered to the customer based on a proportion of the estimated samples that can be reported on for each kit. For clinical customers, we derive revenues from providing our clonoSEQ test report to ordering physicians, and we bill and receive payments from commercial third-party payors and medical institutions. In these transactions, we have identified one performance obligation: the delivery of a clonoSEQ report. As payment from the respective payors may vary based on the various reimbursement rates and patient responsibilities, we consider the transaction price to be variable and record an estimate of the transaction price, subject to the constraint for variable consideration, as revenue at the time of delivery. The estimate of transaction price is based on historical and expected reimbursement rates with the various payors, which are monitored in subsequent periods and adjusted as necessary based on actual collection experience. In January 2019, clonoSEQ received Medicare coverage aligned with the FDA label and National Comprehensive Cancer Network (“NCCN”) guidelines for longitudinal monitoring in multiple myeloma (“MM”) and B cell acute lymphoblastic leukemia (“ALL”). We bill Medicare for an episode of treatment when we deliver the first eligible test results. This billing contemplates all necessary tests required during a patient’s treatment cycle, which is currently estimated at approximately four tests per patient, including the initial sequence identification test. Revenue is recognized at the time the initial billable test result is delivered and is based upon cumulative tests delivered to date. We estimate the number of tests we expect to deliver over a patient’s treatment cycle based on historical testing frequencies for patients by indication. These estimates are subject to change as we develop more information about utilization over time. For the three and nine months ended September 30, 2019, we recognized $0.3 million and $1.1 million relating to the coverage policy, respectively; $0.1 million and $0.4 million of this revenue was related to tests delivered in periods prior to the three and nine months ended September 30, 2019, respectively. Any unrecognized revenue from the initial billable test is recorded as deferred revenue and is recognized as we deliver the remaining tests in a patient’s treatment cycle. Development Revenue We derive revenue by providing services through development agreements to biopharmaceutical customers who seek access to our immune medicine platform technologies. We generate revenues from the delivery of professional support activities pertaining to the use of our proprietary immunoSEQ and clonoSEQ services in the development of the respective customers’ initiatives. The transaction price for these contracts may consist of a combination of non-refundable upfront fees, separately priced sequencing fees, progress based milestones and regulatory milestones. The development agreements may include single or multiple performance obligations depending on the contract. For certain contracts, we may perform services to support the biopharmaceutical customers’ regulatory submission as part of their registrational trials. These services include regulatory support pertaining to our technology intended to be utilized as part of the submission, development of analytical plans for our sequencing data, participation on joint research committees and assistance in completing a regulatory submission. Generally, these services are not distinct within the context of the contract, and they are accounted for as a single performance obligation. When sequencing services are separately priced customer options, we assess if a material right exists and, if not, the customer option to purchase additional sequencing services is not considered part of the contract. Except for any non-refundable upfront fees, the other forms of compensation represent variable consideration. Variable consideration related to progress based and regulatory milestones is estimated using the most likely amount method where variable consideration is constrained until it is probable that a significant reversal of cumulative revenue recognized will not occur. Progress milestones such as the first sample result delivered or final patient enrollment in a customer trial are customer dependent and are included in the transaction price when the respective milestone is probable of occurring. Milestone payments that are not within our customers’ control, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. Determining whether regulatory milestone payments are probable is an area that requires significant judgment. In making this assessment, we evaluate the scientific, clinical, regulatory and other risks that must be managed, as well as the level of effort and investment required to achieve the respective milestone. The primary method used to estimate standalone selling price for performance obligations is the adjusted market assessment approach. Using this approach, we evaluate the market in which we sell our services and estimate the price that a customer in that market would be willing to pay for our services. We recognize revenue using either an input or output measure of progress that faithfully depicts performance on a contract, depending on the contract. The measure used is dependent on the nature of the service to be provided in each contract. Selecting the measure of progress and estimating progress to date requires significant judgment. Deferred Offering Costs Deferred offering costs consist of fees and expenses incurred in connection with the sale of our common stock in the IPO, including legal, accounting, printing and other IPO-related costs. Prior to the completion of our IPO, deferred offering costs were presented in the restricted cash and other assets line item on our unaudited condensed balance sheets. In connection with and as of the closing of our IPO, these costs were reclassified to additional paid-in capital, representing a reduction to the IPO proceeds. As of September 30, 2019, $5.0 million of these IPO-related costs are included in the additional paid-in capital line item on our unaudited condensed balance sheet. Recently Ad opted In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-09, Compensation—Stock Compensation In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other Simplifying the Test for Goodwill Impairment In June 2018, the FASB issued ASU 2018-07, C ompensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting , which expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The guidance is effective for us beginning in 2019, with early adoption permitted. We adopted the guidance effective January 1, 2019 and the adoption did not have any impact on our financial statements. New Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases Leases, In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses Measurement of Credit Losses on Financial Instruments In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other: Internal-Use Software

Revenue

Revenue	9 Months Ended
	Sep. 30, 2019
Revenue From Contract With Customer [Abstract]
Revenue	3. Revenue Translational Development On December 18, 2015, we entered into a translational development agreement with a biopharmaceutical customer for access to certain of our oncology immunosequencing research datasets, including full-time employee support, to accelerate the customer’s preclinical, nonclinical and clinical trial testing. Under the initial terms of the agreement, we could be entitled to up to $40.0 million over a period of four years, which does not include any separately negotiated research sequencing contracts. If the biopharmaceutical customer terminates the agreement prior to the end of the initial four-year research term for any reason other than a material uncured breach by us, then the biopharmaceutical partner has agreed to pay us $0.8 million. In May 2019, the agreement was subsequently amended to reduce the services provided, which in turn reduced the fourth year of eligible payments to $2.3 million. We identified one performance obligation under this agreement, as the services were determined to be highly interrelated. We determined that any separately negotiated sequencing contracts are not performance obligations under the contract, as the contract did not contain any material rights related to such sequencing contracts. For the identified performance obligation, we assessed the work to be performed over the duration of the contract and determined that it is a consistent level of support throughout the period, and therefore, revenue has been recognized straight-line over the contract term. Revenue recognized from this translational development agreement, excluding separately negotiated research sequencing contracts, was $0.6 million and $2.5 million in the three months ended September 30, 2019 and 2018, respectively, and $1.7 million and $7.5 million in the nine months ended September 30, 2019 and 2018, respectively. MRD Development We have entered into agreements with biopharmaceutical customers to further develop and commercialize clonoSEQ and the biopharmaceutical customers’ therapeutics. Under each of the agreements, we received or will receive non-refundable upfront payments and could receive substantial additional payments upon reaching certain progress milestones or achievement of certain regulatory milestones pertaining to the customers’ therapeutic and our clonoSEQ test. Under the contracts, we identify performance obligations, which may include: (i) obligations to provide services supporting the customer’s regulatory submission activities as they relate to our clonoSEQ test; and (ii) sequencing services for customer-provided samples for their regulatory submissions. The transaction price allocated to the respective performance obligations is estimated using an adjusted market assessment approach for the regulatory support services and a standalone selling price for the estimated immunosequencing services. At contract inception, we fully constrained any consideration related to the regulatory milestones, as the achievement of such milestones is subject to third-party regulatory approval and the customers’ own submission decision-making. We recognize revenue relating to the sequencing services over time using an output method based on the proportion of sample results delivered relative to the total amount of sample results expected to be delivered and when expected to be a faithful depiction of progress. We use the same method to recognize the regulatory support services. When an output method based on the proportion of sample results delivered is not expected to be a faithful depiction of progress, we utilize an input method based on estimates of effort completed using a cost-based model. In the three and nine months ended September 30, 2019 and in the three and nine months ended September 30, 2018, we earned $2.0 million and $6.0 million, respectively, in regulatory milestones upon the achievement of regulatory milestones by us and our respective customers’ therapeutics. All $2.0 million and $6.0 million was recognized as revenue within the respective periods, as we determined these amounts were consistent with our estimated standalone selling price and the respective performance obligations were complete. We recognized $2.3 million and $6.1 million in development revenue related to these contracts in the three months ended September 30, 2019 and 2018, respectively, and $3.1 million and $8.0 million in the nine months ended September 30, 2019 and 2018, respectively. As of September 30, 2019, in future periods we could receive up to an additional $129.0 million in milestone payments if certain regulatory approvals are obtained by our customers’ therapeutics in connection with MRD data generated from our clonoSEQ test. Genentech In December 2018, we entered into a worldwide collaboration and license agreement (“Genentech Agreement”) with Genentech, Inc. (“Genentech”) to leverage our capability to develop cellular therapies in oncology. Subsequent to receipt of regulatory approval in January 2019, we received a non-refundable upfront payment of $300.0 million in February 2019 and may be eligible to receive more than $1.8 billion over time, including payments of up to $75.0 million upon the achievement of specified regulatory milestones, up to $300.0 million upon the achievement of specified development milestones and up to $1,430.0 million upon the achievement of specified commercial milestones. In addition, we are separately able to receive tiered royalties at a rate ranging from the mid-single digits to the mid-teens on aggregate worldwide net sales of products arising from the strategic collaboration, subject to certain reductions, with aggregate minimum floors. Under the agreement, we are pursuing two product development pathways for novel T cell immunotherapies in which Genentech intends to use T cell receptors (“TCRs”) screened by our immune medicine platform to engineer and manufacture cellular medicines: • Shared Products. The shared products will use “off-the-shelf” TCRs identified against cancer antigens shared among patients (“Shared Products”). • Personalized Product. The personalized product will use patient-specific TCRs identified by real-time screening of TCRs against cancer antigens in each patient (“Personalized Product”). Under the terms of the agreement, we granted Genentech exclusive worldwide licenses to develop and commercialize TCR-based cellular therapies in the field of oncology, including licenses to existing shared antigen data packages. Additionally, Genentech has the right to determine which product candidates to further develop for commercialization purposes. We determined that this arrangement meets the criteria set forth in ASC Topic 808, Collaborative Arrangements In applying ASC 606, we identified the following performance obligations at the inception of the agreement: 1. License to utilize on an exclusive basis all TCR-specific platform intellectual property to develop and commercialize any licensed products in the field of oncology. 2. License to utilize all data and information within each shared antigen data package and any other know-how disclosed by us to Genentech in oncology. 3. License to utilize all private antigen TCR product data in connection with research and development activities in the field of use. 4. License to existing shared antigen data packages. 5. Research and development services for shared product development including expansion of shared antigen data packages. 6. Research and development services for private product development. 7. Obligations to participate on various joint research, development and project committees. We determined that none of the licenses, research and development services or obligations to participate on various committees were distinct within the context of the contract given such rights and activities were highly interrelated and there was substantial additional research and development to further develop the licenses. We considered factors such as the stage of development of the respective existing antigen data packages, the subsequent development that would be required to both identify and submit a potential target for investigational new drug acceptance under both product pathways and the variability in research and development pathways given Genentech’s control of product commercialization. Specifically, under the agreement, Genentech is not required to pursue development or commercialization activities pertaining to both product pathways and may choose to proceed with one or the other as opposed to both. Accordingly, we determined that all of the identified performance obligations were attributable to one general performance obligation, which is to further the development of our TCR-specific platform, including data packages, and continue to make our TCR identification process available to Genentech to pursue either product pathway. Separately, we have a responsibility to Genentech to enter into a supply and manufacturing agreement for patient specific TCRs as it pertains to any Personalized Product therapeutic. We determined this was an option right of Genentech should they pursue commercialization of a Personalized Product therapy. Because of the uncertainty as a result of the early stage of development, the novel approach of our collaboration with Genentech and our rights to future commercial milestones and royalty payments, we determined that this option right was not a material right that should be accounted for at inception. As such, we will account for the supply and manufacturing agreement when entered into between the parties. We determined the initial transaction price shall be made up of only the $300.0 million upfront, non-refundable payment, as all potential regulatory and development milestone payments were probable of significant revenue reversal since their achievement was highly dependent on factors outside our control. As a result, these payments were fully constrained and were not included in the transaction price as of September 30, 2019. We excluded the commercial milestones and potential royalties from the transaction price as those items relate predominantly to the license rights granted to Genentech and will be assessed when and if such events occur. As there are potential substantive developments necessary, which Genentech may be able to direct, we determined that we would apply a proportional performance model to recognize revenue for our performance obligation. We measure proportional performance using an input method based on costs incurred relative to the total estimated costs of research and development efforts to pursue both the Shared Product and Personalized Product pathways. We currently expect to recognize the revenue over a period of approximately seven to eight years from the effective date. This estimate of the research and development period considers pursuit options of development activities supporting both the Shared Product and the Personalized Product, but may be reduced or increased based on the various activities as directed by the joint committees, decisions made by Genentech, regulatory feedback or other factors not currently known. We recognized revenue of $11.4 million and $26.2 million for the three and nine months ended September 30, 2019, respectively, related to the Genentech collaboration. Costs related to the Genentech collaboration are included in research and development expenses.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	4. Fair Value The following tables set forth the fair value of financial assets and liabilities as of September 30, 2019 and December 31, 2018 that were measured at fair value on a recurring basis (in thousands): September 30, 2019 Level 1 Level 2 Level 3 Total (unaudited) Financial assets Money market funds $ 86,374 $ — $ — $ 86,374 Commercial paper — 136,842 — 136,842 U.S. government debt and agency securities — 419,011 — 419,011 Corporate bonds — 77,940 — 77,940 Total financial assets $ 86,374 $ 633,793 $ — $ 720,167 December 31, 2018 Level 1 Level 2 Level 3 Total Financial assets Money market funds $ 45,998 $ — $ — $ 45,998 Commercial paper — 16,887 — 16,887 U.S. government debt and agency securities — 85,623 — 85,623 Corporate bonds — 7,478 — 7,478 Total financial assets $ 45,998 $ 109,988 $ — $ 155,986 Financial liabilities Convertible preferred stock warrant liability $ — $ — $ 336 $ 336 Total financial liabilities $ — $ — $ 336 $ 336 Level 1 securities include highly liquid money market funds, which we measure the fair value based on quoted prices in active markets for identical assets or liabilities. Level 2 securities consist of U.S. government debt securities, U.S. government agency securities, commercial paper and corporate bonds, and are valued based on recent trades of securities in inactive markets or based on quoted market prices of similar instruments and other significant inputs derived from or corroborated by observable market data. Level 3 liabilities that were measured at fair value on a recurring basis consisted of a convertible preferred stock warrant liability. During the nine months ended September 30, 2019 and prior to the completion of our IPO on July 1, 2019, we recognized $2.3 million of expense related to the revaluation of the convertible preferred stock warrant liability in the interest and other income, net line item on our unaudited condensed statements of operations. Immediately prior to the completion of our IPO, the convertible preferred stock warrant liability converted to a common stock warrant and the financial liability was reclassified to the additional paid-in capital line item on our unaudited condensed balance sheet, thereby concluding the need for revaluation.

Investments

Investments	9 Months Ended
	Sep. 30, 2019
Investments Debt And Equity Securities [Abstract]
Investments	5. Investments Available-for-sale investments consisted of the following as of September 30, 2019 and December 31, 2018 (in thousands): September 30, 2019 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value (unaudited) Short-term marketable securities Commercial paper $ 136,843 $ — $ — $ 136,843 U.S. government debt and agency securities 331,770 354 (15 ) 332,109 Corporate bonds 29,486 49 — 29,535 Total short-term marketable securities $ 498,099 $ 403 $ (15 ) $ 498,487 Long-term marketable securities: U.S. government debt and agency securities $ 86,813 $ 112 $ (23 ) $ 86,902 Corporate bonds 48,309 95 — 48,404 Total long-term marketable securities $ 135,122 $ 207 $ (23 ) $ 135,306 December 31, 2018 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Short-term marketable securities Commercial paper $ 16,887 $ — $ — $ 16,887 U.S. government debt and agency securities 85,722 — (99 ) 85,623 Corporate bonds 7,486 — (8 ) 7,478 Total short-term marketable securities $ 110,095 $ — $ (107 ) $ 109,988 The following table presents the gross unrealized holding losses and fair value for investments in an unrealized loss position, and the length of time that individual securities have been in a continuous loss position, as of September 30, 2019 (in thousands): Less Than 12 Months 12 Months Or Greater Fair Value Unrealized Loss Fair Value Unrealized Loss (unaudited) U.S. government debt and agency securities $ 53,975 $ (38 ) $ — $ — Total available-for-sale securities $ 53,975 $ (38 ) $ — $ — We evaluated our securities for other-than-temporary impairment and considered the decline in market value for the securities to be primarily attributable to current economic and market conditions. It is not more likely than not that we will be required to sell the securities, and we do not intend to do so prior to the recovery of the amortized cost basis. Based on this analysis, these marketable securities were not considered to be other-than-temporarily impaired as of September 30, 2019. All the commercial paper, U.S. government debt and agency securities and corporate bonds designated as short-term marketable securities have an effective maturity date that is less than one year from September 30, 2019. Those that are designated as long-term marketable securities have an effective maturity date that is more than one year from September 30, 2019.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	9 Months Ended
	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	6. Goodwill There have been no changes in the carrying amount of goodwill since its recognition in 2015. Intangible assets subject to amortization as of September 30, 2019 and December 31, 2018 consisted of the following (in thousands): September 30, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount (unaudited) Acquired developed technology $ 20,000 $ (7,882 ) $ 12,118 Purchased intellectual property 325 (87 ) 238 Balance at September 30, 2019 $ 20,325 $ (7,969 ) $ 12,356 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Acquired developed technology $ 20,000 $ (6,636 ) $ 13,364 Purchased intellectual property 325 (63 ) 262 Balance at December 31, 2018 $ 20,325 $ (6,699 ) $ 13,626 The developed technology was acquired in connection with our acquisition of Sequenta, Inc. (“Sequenta”) in 2015. The remaining balance of the acquired technology and the purchased intellectual property is expected to be amortized over the next approximately 7.3 years. As of September 30, 2019, expected future amortization expense for intangible assets was as follows (in thousands) (unaudited): 2019 $ 428 2020 1,698 2021 1,698 2022 1,698 2023 1,698 Thereafter 5,136 Total future amortization expense $ 12,356

Deferred Revenue

Deferred Revenue	9 Months Ended
	Sep. 30, 2019
Revenue From Contract With Customer [Abstract]
Deferred Revenue	7. Deferred Revenue Deferred revenue by revenue classification as of September 30, 2019 and December 31, 2018 was as follows (in thousands): September 30, 2019 December 31, 2018 (unaudited) Current deferred revenue Sequencing $ 12,419 $ 11,238 Development 48,850 1,457 Total current deferred revenue 61,269 12,695 Non-current deferred revenue Sequencing 1,195 516 Development 227,144 188 Total non-current deferred revenue 228,339 704 Total current and non-current deferred revenue $ 289,608 $ 13,399 Genentech deferred revenue represents $47.4 million and $226.4 million of the current and non-current development deferred revenue balances, respectively, at September 30, 2019. In general, the current amounts will be recognized as revenue within 12 months and the non-current amounts will be recognized as revenue over a period of approximately seven to eight years. This period of time represents an estimate of the research and development period to develop cellular therapies in oncology, which may be reduced or increased based on the various development activities. Changes in deferred revenue during the nine months ended September 30, 2019 were as follows (in thousands): Deferred revenue balance at December 31, 2018 $ 13,399 Additions to deferred revenue during the period (unaudited) 312,248 Revenue recognized during the period (unaudited) (36,039 ) Deferred revenue balance at September 30, 2019 (unaudited) $ 289,608 As of September 30, 2019, $6.4 million was recognized that was included in the deferred revenue balance at December 31, 2018. As a result of cancelled customer sequencing contracts, we recognized $1.5 million of sequencing revenue during the nine months ended September 30, 2019.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	8. Commitments and Contingencies Operating Leases We have entered into various non-cancelable lease agreements for our office and laboratory spaces. In July 2011, we entered into a non-cancelable lease agreement with a minority shareholder for our current headquarters in Seattle, Washington. The lease terms were subsequently amended multiple times, most recently in August 2019, when we expanded the existing premises. Rent obligations of the expanded premises commence four months after the landlord delivers the expanded premises to us for construction of certain tenant improvements, and the lease term for both the existing premises and the expanded premises ends 142 months after the commencement date of the new lease mentioned below, subject to our option to twice extend the lease for five years. If the new lease mentioned below does not commence, the lease term for the existing premises and the expanded premises ends March 31, 2024. The amended lease also requires us to pay additional amounts for operating and maintenance expenses. In August 2019, we entered into an operating lease to rent 100,000 square feet in a to-be-constructed building in Seattle, Washington. Shell construction is expected to be completed in 2020. The lease term commences on the date that the landlord delivers the premises to us for construction of certain tenant improvements. Rent obligations commence 10 months thereafter, and the lease term ends 142 months from the date rent commences, subject to our option to twice extend the lease for five years. The lease is cancellable under certain circumstances if the landlord fails to deliver the premises to us by May 1, 2021. We plan to occupy the new building in 2021, once interior construction is finished. In connection with the lease, the landlord agreed to fund $20.0 million in improvements. The lease also requires us to pay additional amounts for operating and maintenance expenses. Furthermore, in connection with the lease, we entered into a letter of credit of $2.1 million with one of our existing financial institutions. In October 2016, we entered into an agreement to sublease certain laboratory and office space in South San Francisco, California. The lease commenced in October 2016 and terminated in March 2019. The lease require d us to pay additional amounts for operating and maintenance expenses. In April 2018, we entered into a lease agreement to lease additional space in South San Francisco, California. The lease term is through March 2026 and provides for one five-year option. We will be responsible for our share of allocable operating expenses, tax expenses and utilities cost during the duration of the lease term. In connection with the lease, the landlord funded agreed-upon improvements prior to the lease commencement date of December 12, 2018. The landlord was solely responsible for the $2.4 million cost of such improvements, which we recognized as a leasehold improvement asset that depreciates beginning from the commencement date to the initial lease term, and a corresponding leasehold incentive obligation, which is amortized over the life of the lease. As of September 30, 2019, future minimum lease payments, exclusive of operating and maintenance costs and inclusive of payments to be made under the financing obligation, were as follows (in thousands) (unaudited): 2019 $ 901 2020 3,963 2021 6,745 2022 10,681 2023 10,985 Thereafter 107,570 Total future minimum lease payments $ 140,845 Rent expenses, inclusive of operating and maintenance costs, were $1.3 million and $1.1 million for the three months ended September 30, 2019 and 2018, respectively, and $3.6 million and $2.9 million for the nine months ended September 30, 2019 and 2018, respectively. Legal Proceedings We are subject to claims and assessments from time to time in the ordinary course of business. We will accrue a liability for such matters when it is probable that a liability has been incurred and the amount can be reasonably estimated. When only a range of possible loss can be established, the most probable amount in the range is accrued. If no amount within this range is a better estimate than any other amount within the range, the minimum amount in the range is accrued. We are not currently party to any material legal proceedings. Indemnification Agreements In the ordinary course of business, we may provide indemnification of varying scope and terms to vendors, lessors, customers and other parties with respect to certain matters including, but not limited to, losses arising out of breach of our agreements with them or from intellectual property infringement claims made by third parties. In addition, we have entered into indemnification agreements with members of our Board of Directors and certain of our executive officers that will require us to indemnify them against certain liabilities that may arise by reason of their status or service as directors or officers. The maximum potential amount of future payments that we could be required to make under these indemnification agreements is, in many cases, unlimited. We have not incurred any material costs as a result of such indemnifications and are not currently aware of any indemnification claims.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Shareholders' Equity	9 . Shareholders’ Equity Convertible Preferred Stock Immediately prior to the completion of our IPO on July 1, 2019, 93,039,737 shares of convertible preferred stock then outstanding converted into an equivalent number of shares of common stock. As of September 30, 2019, no shares of convertible preferred stock were outstanding. Preferred Stock We are authorized to issue 10,000,000 shares of preferred stock, par value $0.0001 per share. As of September 30, 2019, no shares of preferred stock were outstanding. Common Stock We are authorized to issue 340,000,000 shares of common stock. Our common stock has a par value of $0.0001, no preferences or privileges and is not redeemable. Holders of our common stock are entitled to one vote for each share of common stock held. As of September 30, 2019, we had 124,316,080 shares of common stock outstanding. We have reserved shares of common stock for the following as of September 30, 2019 (unaudited): Shares issuable upon the exercise of outstanding common stock options and the vesting of outstanding common restricted stock units ("RSUs") granted 17,495,253 Shares available for future grant under the 2019 Plan 15,474,217 Shares available for future grant under the Employee Stock Purchase Plan 1,551,917 Shares to be issued upon conversion of a common stock warrant 56,875 Total shares of common stock reserved for future issuance 34,578,262 Common In connection with two transactions in 2012 and 2013, we granted warrants to purchase up to 55,032 shares of common stock. These warrants were exercisable at any time for a period of ten years from the date of issuance at a weighted-average exercise price of $0.37, except in the case of a warrant to purchase 20,000 shares of common stock at an exercise price of $0.45 per share that would have expired if unexercised prior to the closing of our IPO. On July 1, 2019, we issued 54,792 shares of common stock through both a cash and cashless exercise of the warrants. The impact of these exercises is immaterial to the unaudited condensed financial statements. Separately, in 2014, we issued a warrant to purchase 56,875 shares of Series C convertible preferred stock at an exercise price of $2.64. The warrant was exercisable at any time for a period of seven years from the date of issuance. Immediately prior to and in connection with the completion of our IPO, this convertible preferred stock warrant, which was recorded as a financial liability, was converted to a warrant to purchase the same number of shares of common stock. Upon conversion, the financial liability was reclassified to the additional paid-in capital line item on our unaudited condensed balance sheet. The warrant to purchase 56,875 shares of common stock remains outstanding at September 30, 2019.

Equity Incentive Plans

Equity Incentive Plans	9 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Equity Incentive Plans	1 0 . Equity Incentive Plans Sequenta 2008 Stock Plan, as amended In connection with our acquisition of Sequenta in January 2015, we assumed Sequenta’s Equity Incentive Plan (“2008 Plan”), including all outstanding options and shares available for future issuance under the 2008 Plan, which, prior to the completion of our IPO, were all exercisable for Series E-1 convertible preferred stock. Upon completion of our IPO, outstanding options are now exercisable for common stock. While no shares are available for future issuance under this plan, the 2008 Plan continues to govern outstanding equity awards granted thereunder. Adaptive 2009 Equity Incentive Plan We adopted an equity incentive plan in 2009 (“2009 Plan”) that provided for the issuance of incentive and nonqualified common stock options, and other share-based awards for employees, directors and consultants. Under the 2009 Plan, the option exercise price for incentive and nonqualified stock options were not to be less than the fair market value of our common stock at the date of grant as determined by our Board of Directors. Options granted under this plan expire no later than ten years from the grant date, and vesting was established at the time of grant. Pursuant to the terms of the 2019 Plan, any shares subject to outstanding options originally granted under the 2009 Plan that terminate, expire or lapse for any reason without the delivery of shares to the holder thereof shall become available for issuance pursuant to awards granted under the 2019 Plan. While no shares are available for future issuance under the 2009 Plan, it continues to govern outstanding equity awards granted thereunder. 2019 Equity Incentive Plan The 2019 Plan was approved by our shareholders on June 13, 2019 and, pursuant to the resolutions adopted by our Board of Directors, became effective with an initial reserve of 15,519,170 shares immediately prior to and contingent upon the closing of our IPO. The 2019 Plan provides for the issuance of awards in the form of options and other share-based awards for employees, directors and consultants. Under the 2019 Plan, the option exercise price per share shall not be less than the fair market value of a share of stock on the grant date of the option, as defined by the 2019 Plan, unless explicitly qualified under the provisions of Section 409A or Section 424(a) of the Internal Revenue Code of 1986. Additionally, unless otherwise specified, options granted under this plan expire no later than ten years from the grant date, and vesting is established at the time of grant. Changes in shares available for grant during the nine months ended September 30, 2019 were as follows: Shares Available for Grant Shares available for grant at December 31, 2018 6,827,996 2019 Plan reserve (unaudited) 12,363,202 Options and RSUs granted (unaudited) (4,084,656 ) Options and RSUs forfeited or cancelled (unaudited) 367,675 Shares available for grant at September 30, 2019 (unaudited) 15,474,217 Stock option activity under the 2008 Plan, 2009 Plan and 2019 Plan during the nine months ended September 30, 2019 is as follows: Shares Subject to Outstanding Options Weighted- Average Exercise Price per Share Aggregate Intrinsic Value (in thousands) Options outstanding at December 31, 2018 15,157,930 $ 4.52 $ 41,690 Options granted (unaudited) 4,071,846 9.15 Options forfeited or cancelled (unaudited) (367,675 ) 6.08 Options exercised (unaudited) (1,379,658 ) 1.67 Options outstanding at September 30, 2019 (unaudited) 17,482,443 5.79 438,968 During the nine months ended September 30, 2019, we granted 12,810 shares of RSUs at a weighted-average grant date fair value per share of $41.63, all of which have not vested and remain outstanding at September 30, 2019. Fair Value of Options Granted The estimated fair value of options granted during the nine months ended September 30, 2019 and 2018 was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions: Nine Months Ended September 30, 2019 2018 (unaudited) Grant date fair value $ 10.08 $ 6.55 Expected term (in years) 6.06 6.15 Risk-free interest rate 2.4 % 2.7 % Expected volatility 68.0 % 68.9 % Expected dividend yield — — The determination of the fair value of stock options on the date of grant using a Black-Scholes option-pricing model is affected by the estimated fair value of our common stock, as well as assumptions regarding a number of variables that are complex, subjective and generally require significant judgment to determine. The valuation assumptions were determined as follows: Fair value of common stock— The grant date fair value of our common stock has been determined by our Board of Directors with input from management. Prior to the closing of our IPO, the grant date fair value of the common stock was determined using valuation methodologies which utilize certain assumptions, including probability weighting of events, volatility, time to liquidation, a risk-free interest rate and an assumption for a discount for lack of marketability (Level 3 inputs). In determining the fair value of the common stock, the methodologies used to estimate the enterprise value were performed using methodologies, approaches and assumptions consistent with the American Institute of Certified Public Accountants Accounting and Valuation Guide, Valuation of Privately-Held-Company Equity Securities Issued as Compensation. For valuations of grants made after the closing of our IPO, our Board of Directors determines the fair value of each share of common stock based on the closing price of our common stock on the date of grant or other relevant determination date, as reported on The Nasdaq Global Select Market. Expected term —The expected life of options granted to employees and non-employee directors is determined using the “simplified” method, as illustrated in ASC Topic 718, , as we do not have sufficient exercise history to determine a better estimate of expected term. Under this approach, the expected term is presumed to be the average of the weighted-average vesting term and the contractual term of the option. Risk-free interest rate —We utilize a risk-free interest rate in the option valuation model based on U.S. Treasury zero-coupon issues, with remaining terms similar to the expected term of the options. Expected volatility —As we do not have sufficient trading history for our common stock, the expected volatility is based on the historical volatility of our publicly traded industry peers utilizing a period of time consistent with our estimate of the expected term. Expected dividend yield —We do not anticipate paying any cash dividends in the foreseeable future and, therefore, use an expected dividend yield of zero in the option valuation model. Share-based compensation expense of $3.3 million and $2.6 million was recognized during the three months ended September 30, 2019 and 2018, respectively, and $9.7 million and $8.1 million was recognized during the nine months ended September 30, 2019 and 2018, respectively. The compensation costs for the three and nine months ended September 30, 2019 and 2018, respectively, related to stock options and RSUs are included on our unaudited condensed statements of operations as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (unaudited) Cost of revenue $ 133 $ 97 $ 376 $ 273 Research and development 943 700 2,838 2,168 Sales and marketing 798 620 2,647 2,169 General and administration 1,461 1,136 3,852 3,493 Total share-based compensation expense $ 3,335 $ 2,553 $ 9,713 $ 8,103 At September 30, 2019, unrecognized share-based compensation expense related to unvested stock options was $34.5 million, which is expected to be recognized over a remaining weighted-average period of 3.06 years. Additionally, at September 30, 2019, unrecognized share-based compensation expense related to unvested RSUs was $0.3 million, which is expected to be recognized over a remaining weighted-average period of 0.73 years.

Net Loss Per Share Attributable

Net Loss Per Share Attributable to Common Shareholders	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Net Loss Per Share Attributable to Common Shareholders	1 1 . Net Loss Shareholders Net Loss The following table sets forth the computation of the basic and diluted net loss per share attributable to common shareholders for the three and nine months ended September 30, 2019 and 2018, respectively (in thousands, except shares and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (unaudited) Net loss $ (13,950 ) $ (8,292 ) $ (47,995 ) $ (33,176 ) Fair value adjustments to redemption value for Series E-1 convertible preferred stock options — (4 ) (964 ) (2 ) Net loss attributable to common shareholders, basic and diluted $ (13,950 ) $ (8,296 ) $ (48,959 ) $ (33,178 ) Weighted-average shares used in computing net loss per share 124,285,686 12,620,010 50,552,389 12,430,535 Net loss per share attributable to common shareholders, basic and diluted $ (0.11 ) $ (0.66 ) $ (0.97 ) $ (2.67 ) Since we were in a loss position for all periods presented, basic net loss per share attributable to common shareholders is the same as diluted net loss per share attributable to common shareholders, as the inclusion of all potential shares of common stock outstanding would have been anti-dilutive. The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share attributable to common shareholders for the three and nine months ended September 30, 2019 and 2018, respectively, as they had an anti-dilutive effect: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (unaudited) Convertible preferred stock (on as if converted basis) — 92,790,094 61,641,506 92,764,348 Stock options issued and outstanding 17,466,409 14,801,784 17,096,516 14,489,718 Unvested restricted stock units 7,380 — 2,487 — Common stock warrants 56,875 55,032 55,653 55,032 Convertible preferred stock warrant — 56,875 37,708 56,875 Total 17,530,664 107,703,785 78,833,870 107,365,973

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make certain estimates, judgments and assumptions that affect the reported amounts of assets and liabilities and the related disclosures at the date of the financial statements, as well as the reported amounts of revenues and expenses during the periods presented. We base our estimates on historical experience and other relevant assumptions that we believe to be reasonable under the circumstances. Estimates are used in several areas including, but not limited to, estimates of progress to date for certain performance obligations and the transaction price for certain contracts with customers, share-based compensation, including the fair value of stock, the provision for income taxes, including related reserves, and goodwill, among others. These estimates generally involve complex issues and require judgments, involve the analysis of historical results and prediction of future trends, can require extended periods of time to resolve and are subject to change from period to period. Actual results may differ materially from management’s estimates.
Unaudited Interim Condensed Financial Statements	Unaudited Interim Condensed Financial Statements In our opinion, the accompanying unaudited condensed financial statements have been prepared in accordance with GAAP for interim financial information. These unaudited condensed financial statements include all adjustments necessary to fairly state the financial position and the results of our operations and cash flows for interim periods in accordance with GAAP. Interim-period results are not necessarily indicative of results of operations or cash flows for a full year or any subsequent interim period. The accompanying unaudited condensed financial statements should be read in conjunction with our audited financial statements and notes included in our prospectus dated June 26, 2019 filed with the Securities and Exchange Commission (“SEC”) on June 27, 2019 in connection with our IPO (“Prospectus”).
Reclassifications	Reclassifications In the accompanying audited condensed balance sheet, certain prior year amounts have been reclassified to conform to the current period presentation. Specifically, “restricted cash” and “other assets” were previously included together in the restricted cash and other assets line item and are now separately stated. There was no change to total assets as a result of the reclassification.
Restricted Cash	Restricted Cash We are required to maintain certain balances under lease arrangements for our property and facilities leases. We had restricted cash of $2.1 million and $0.1 million as of September 30, 2019 and December 31, 2018, respectively.
Concentrations of Risk	Concentrations We are subject to a concentration of risk from a limited number of suppliers, or in some cases, single suppliers for some of our laboratory instruments and materials. This risk is managed by targeting a quantity of surplus stock. Cash, cash equivalents and marketable securities are financial instruments that potentially subject us to concentrations of credit risk. We invest in money market funds, U.S. government debt securities, U.S. government agency securities, commercial paper and corporate bonds with high-quality accredited financial institutions. Significant customers are those which represent more than 10% of our total revenue or accounts receivable, net balances at each respective balance sheet date. Revenue from these customers reflects their purchase of our products and services and our collaboration efforts with Genentech. For each significant customer, revenue as a percentage of total revenue for the periods presented and accounts receivable, net as a percentage of total accounts receivable, net as of the periods presented were as follows: Revenue Accounts Receivable, Net Three Months Ended September 30, Nine Months Ended September 30, September 30, December 31, 2019 2018 2019 2018 2019 2018 (unaudited) (unaudited) Customer A 16.0% 15.7% 11.8% 21.6% 39.6% *% Customer B 10.7 * * * * 15.1 Customer C * 35.0 * 19.1 * 13.2 Genentech, Inc. 43.9 * 43.7 * * * * less than 10%
Leases	Leases Operating Lease Arrangements We have operating lease agreements for the laboratory and office facilities that we occupy. Rent expense is recognized on a straight-line basis over the term of the lease. Incentives granted under our facility leases, including rent holidays, are capitalized and are recognized as adjustments to rental expense on a straight-line basis over the term of the lease. Lease Financing Arrangements Due to our significant involvement during the construction process of a leased building, we qualify as the deemed owner of the building under build-to-suit lease accounting guidance. The cost of the related building is recorded in property and equipment, net and the offsetting lease financing obligation is recorded as a long-term financing obligation on our unaudited condensed balance sheet. As of September 30, 2019, $23.4 million of building costs have been recorded in property and equipment, net.
Revenue Recognition	Revenue We recognize revenue in accordance with Accounting Standards Codification (“ASC”) Topic 606 (“ASC 606”), Revenue from Contracts with Customers Overview Our revenue is generated from immunosequencing (“sequencing”) products and services (“sequencing revenue”) and from regulatory or development support services leveraging our immune medicine platform (“development revenue”). When revenue generating contracts have elements of both sequencing revenue and development revenue, we allocate revenue based on the nature of the performance obligation and the allocated transaction price. Sequencing Revenue Sequencing revenue reflects the amounts generated from providing sequencing services and testing through our immunoSEQ and clonoSEQ products and services to our research and clinical customers, respectively. For research customers, contracts typically include an amount billed in advance of services (“upfront”), and subsequent billings as sample results are delivered to the customer. Upfront amounts received are recorded as deferred revenue, which we recognize as revenue upon satisfaction of performance obligations. We have identified two typical performance obligations under the terms of our research service contracts: sequencing services and related data analysis. We recognize revenue for both identified performance obligations as sample results are delivered to the customer. For other research customers who choose to purchase a research use only kit, the kits are sold on a price per kit basis with amounts payable upon delivery of the kit. Payments received are recorded as deferred revenue. For these customers, we have identified one performance obligation: the delivery of sample results. We recognize revenue as the results are delivered to the customer based on a proportion of the estimated samples that can be reported on for each kit. For clinical customers, we derive revenues from providing our clonoSEQ test report to ordering physicians, and we bill and receive payments from commercial third-party payors and medical institutions. In these transactions, we have identified one performance obligation: the delivery of a clonoSEQ report. As payment from the respective payors may vary based on the various reimbursement rates and patient responsibilities, we consider the transaction price to be variable and record an estimate of the transaction price, subject to the constraint for variable consideration, as revenue at the time of delivery. The estimate of transaction price is based on historical and expected reimbursement rates with the various payors, which are monitored in subsequent periods and adjusted as necessary based on actual collection experience. In January 2019, clonoSEQ received Medicare coverage aligned with the FDA label and National Comprehensive Cancer Network (“NCCN”) guidelines for longitudinal monitoring in multiple myeloma (“MM”) and B cell acute lymphoblastic leukemia (“ALL”). We bill Medicare for an episode of treatment when we deliver the first eligible test results. This billing contemplates all necessary tests required during a patient’s treatment cycle, which is currently estimated at approximately four tests per patient, including the initial sequence identification test. Revenue is recognized at the time the initial billable test result is delivered and is based upon cumulative tests delivered to date. We estimate the number of tests we expect to deliver over a patient’s treatment cycle based on historical testing frequencies for patients by indication. These estimates are subject to change as we develop more information about utilization over time. For the three and nine months ended September 30, 2019, we recognized $0.3 million and $1.1 million relating to the coverage policy, respectively; $0.1 million and $0.4 million of this revenue was related to tests delivered in periods prior to the three and nine months ended September 30, 2019, respectively. Any unrecognized revenue from the initial billable test is recorded as deferred revenue and is recognized as we deliver the remaining tests in a patient’s treatment cycle. Development Revenue We derive revenue by providing services through development agreements to biopharmaceutical customers who seek access to our immune medicine platform technologies. We generate revenues from the delivery of professional support activities pertaining to the use of our proprietary immunoSEQ and clonoSEQ services in the development of the respective customers’ initiatives. The transaction price for these contracts may consist of a combination of non-refundable upfront fees, separately priced sequencing fees, progress based milestones and regulatory milestones. The development agreements may include single or multiple performance obligations depending on the contract. For certain contracts, we may perform services to support the biopharmaceutical customers’ regulatory submission as part of their registrational trials. These services include regulatory support pertaining to our technology intended to be utilized as part of the submission, development of analytical plans for our sequencing data, participation on joint research committees and assistance in completing a regulatory submission. Generally, these services are not distinct within the context of the contract, and they are accounted for as a single performance obligation. When sequencing services are separately priced customer options, we assess if a material right exists and, if not, the customer option to purchase additional sequencing services is not considered part of the contract. Except for any non-refundable upfront fees, the other forms of compensation represent variable consideration. Variable consideration related to progress based and regulatory milestones is estimated using the most likely amount method where variable consideration is constrained until it is probable that a significant reversal of cumulative revenue recognized will not occur. Progress milestones such as the first sample result delivered or final patient enrollment in a customer trial are customer dependent and are included in the transaction price when the respective milestone is probable of occurring. Milestone payments that are not within our customers’ control, such as regulatory approvals, are not considered probable of being achieved until those approvals are received. Determining whether regulatory milestone payments are probable is an area that requires significant judgment. In making this assessment, we evaluate the scientific, clinical, regulatory and other risks that must be managed, as well as the level of effort and investment required to achieve the respective milestone. The primary method used to estimate standalone selling price for performance obligations is the adjusted market assessment approach. Using this approach, we evaluate the market in which we sell our services and estimate the price that a customer in that market would be willing to pay for our services. We recognize revenue using either an input or output measure of progress that faithfully depicts performance on a contract, depending on the contract. The measure used is dependent on the nature of the service to be provided in each contract. Selecting the measure of progress and estimating progress to date requires significant judgment.
Deferred Offering Costs	Deferred Offering Costs Deferred offering costs consist of fees and expenses incurred in connection with the sale of our common stock in the IPO, including legal, accounting, printing and other IPO-related costs. Prior to the completion of our IPO, deferred offering costs were presented in the restricted cash and other assets line item on our unaudited condensed balance sheets. In connection with and as of the closing of our IPO, these costs were reclassified to additional paid-in capital, representing a reduction to the IPO proceeds. As of September 30, 2019, $5.0 million of these IPO-related costs are included in the additional paid-in capital line item on our unaudited condensed balance sheet.
Recently Adopted Accounting Pronouncements	Recently Ad opted In March 2016, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2016-09, Compensation—Stock Compensation In January 2017, the FASB issued ASU No. 2017-04, Intangibles—Goodwill and Other Simplifying the Test for Goodwill Impairment In June 2018, the FASB issued ASU 2018-07, C ompensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting , which expands the scope of Topic 718 to include share-based payment transactions for acquiring goods and services from nonemployees. The guidance is effective for us beginning in 2019, with early adoption permitted. We adopted the guidance effective January 1, 2019 and the adoption did not have any impact on our financial statements.
New Accounting Pronouncements Not Yet Adopted	New Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU No. 2016-02, Leases Leases, In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses Measurement of Credit Losses on Financial Instruments In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other: Internal-Use Software

Significant Accounting Polici_3

Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Schedule of Concentrations of Risk Percentage	For each significant customer, revenue as a percentage of total revenue for the periods presented and accounts receivable, net as a percentage of total accounts receivable, net as of the periods presented were as follows: Revenue Accounts Receivable, Net Three Months Ended September 30, Nine Months Ended September 30, September 30, December 31, 2019 2018 2019 2018 2019 2018 (unaudited) (unaudited) Customer A 16.0% 15.7% 11.8% 21.6% 39.6% *% Customer B 10.7 * * * * 15.1 Customer C * 35.0 * 19.1 * 13.2 Genentech, Inc. 43.9 * 43.7 * * * * less than 10%

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables set forth the fair value of financial assets and liabilities as of September 30, 2019 and December 31, 2018 that were measured at fair value on a recurring basis (in thousands): September 30, 2019 Level 1 Level 2 Level 3 Total (unaudited) Financial assets Money market funds $ 86,374 $ — $ — $ 86,374 Commercial paper — 136,842 — 136,842 U.S. government debt and agency securities — 419,011 — 419,011 Corporate bonds — 77,940 — 77,940 Total financial assets $ 86,374 $ 633,793 $ — $ 720,167 December 31, 2018 Level 1 Level 2 Level 3 Total Financial assets Money market funds $ 45,998 $ — $ — $ 45,998 Commercial paper — 16,887 — 16,887 U.S. government debt and agency securities — 85,623 — 85,623 Corporate bonds — 7,478 — 7,478 Total financial assets $ 45,998 $ 109,988 $ — $ 155,986 Financial liabilities Convertible preferred stock warrant liability $ — $ — $ 336 $ 336 Total financial liabilities $ — $ — $ 336 $ 336

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2019
Investments Debt And Equity Securities [Abstract]
Schedule of Available-for-sale Investments	Available-for-sale investments consisted of the following as of September 30, 2019 and December 31, 2018 (in thousands): September 30, 2019 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value (unaudited) Short-term marketable securities Commercial paper $ 136,843 $ — $ — $ 136,843 U.S. government debt and agency securities 331,770 354 (15 ) 332,109 Corporate bonds 29,486 49 — 29,535 Total short-term marketable securities $ 498,099 $ 403 $ (15 ) $ 498,487 Long-term marketable securities: U.S. government debt and agency securities $ 86,813 $ 112 $ (23 ) $ 86,902 Corporate bonds 48,309 95 — 48,404 Total long-term marketable securities $ 135,122 $ 207 $ (23 ) $ 135,306 December 31, 2018 Amortized Cost Unrealized Gain Unrealized Loss Estimated Fair Value Short-term marketable securities Commercial paper $ 16,887 $ — $ — $ 16,887 U.S. government debt and agency securities 85,722 — (99 ) 85,623 Corporate bonds 7,486 — (8 ) 7,478 Total short-term marketable securities $ 110,095 $ — $ (107 ) $ 109,988
Schedule of Gross Unrealized Holding Losses and Fair Value for Investments in Unrealized Loss Position	The following table presents the gross unrealized holding losses and fair value for investments in an unrealized loss position, and the length of time that individual securities have been in a continuous loss position, as of September 30, 2019 (in thousands): Less Than 12 Months 12 Months Or Greater Fair Value Unrealized Loss Fair Value Unrealized Loss (unaudited) U.S. government debt and agency securities $ 53,975 $ (38 ) $ — $ — Total available-for-sale securities $ 53,975 $ (38 ) $ — $ —

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill And Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets Subject to Amortization	Intangible assets subject to amortization as of September 30, 2019 and December 31, 2018 consisted of the following (in thousands): September 30, 2019 Gross Carrying Amount Accumulated Amortization Net Carrying Amount (unaudited) Acquired developed technology $ 20,000 $ (7,882 ) $ 12,118 Purchased intellectual property 325 (87 ) 238 Balance at September 30, 2019 $ 20,325 $ (7,969 ) $ 12,356 December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Acquired developed technology $ 20,000 $ (6,636 ) $ 13,364 Purchased intellectual property 325 (63 ) 262 Balance at December 31, 2018 $ 20,325 $ (6,699 ) $ 13,626
Schedule of Future Amortization Expense for Intangible Assets	As of September 30, 2019, expected future amortization expense for intangible assets was as follows (in thousands) (unaudited): 2019 $ 428 2020 1,698 2021 1,698 2022 1,698 2023 1,698 Thereafter 5,136 Total future amortization expense $ 12,356

Deferred Revenue (Tables)

Deferred Revenue (Tables)	9 Months Ended
	Sep. 30, 2019
Revenue From Contract With Customer [Abstract]
Deferred Revenue by Revenue Classification	Deferred revenue by revenue classification as of September 30, 2019 and December 31, 2018 was as follows (in thousands): September 30, 2019 December 31, 2018 (unaudited) Current deferred revenue Sequencing $ 12,419 $ 11,238 Development 48,850 1,457 Total current deferred revenue 61,269 12,695 Non-current deferred revenue Sequencing 1,195 516 Development 227,144 188 Total non-current deferred revenue 228,339 704 Total current and non-current deferred revenue $ 289,608 $ 13,399
Changes in Deferred Revenue	Changes in deferred revenue during the nine months ended September 30, 2019 were as follows (in thousands): Deferred revenue balance at December 31, 2018 $ 13,399 Additions to deferred revenue during the period (unaudited) 312,248 Revenue recognized during the period (unaudited) (36,039 ) Deferred revenue balance at September 30, 2019 (unaudited) $ 289,608

Commitments and Contingencies (

Commitments and Contingencies (Tables)	9 Months Ended
	Sep. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	As of September 30, 2019, future minimum lease payments, exclusive of operating and maintenance costs and inclusive of payments to be made under the financing obligation, were as follows (in thousands) (unaudited): 2019 $ 901 2020 3,963 2021 6,745 2022 10,681 2023 10,985 Thereafter 107,570 Total future minimum lease payments $ 140,845

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Summary of Reserved Shares of Common Stock	We have reserved shares of common stock for the following as of September 30, 2019 (unaudited): Shares issuable upon the exercise of outstanding common stock options and the vesting of outstanding common restricted stock units ("RSUs") granted 17,495,253 Shares available for future grant under the 2019 Plan 15,474,217 Shares available for future grant under the Employee Stock Purchase Plan 1,551,917 Shares to be issued upon conversion of a common stock warrant 56,875 Total shares of common stock reserved for future issuance 34,578,262

Equity Incentive Plans (Tables)

Equity Incentive Plans (Tables)	9 Months Ended
	Sep. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Changes in Shares Available for Grant	Changes in shares available for grant during the nine months ended September 30, 2019 were as follows: Shares Available for Grant Shares available for grant at December 31, 2018 6,827,996 2019 Plan reserve (unaudited) 12,363,202 Options and RSUs granted (unaudited) (4,084,656 ) Options and RSUs forfeited or cancelled (unaudited) 367,675 Shares available for grant at September 30, 2019 (unaudited) 15,474,217
Summary of Stock Option Activity Under 2008 Plan 2009 Plan and 2019 Plan	Stock option activity under the 2008 Plan, 2009 Plan and 2019 Plan during the nine months ended September 30, 2019 is as follows: Shares Subject to Outstanding Options Weighted- Average Exercise Price per Share Aggregate Intrinsic Value (in thousands) Options outstanding at December 31, 2018 15,157,930 $ 4.52 $ 41,690 Options granted (unaudited) 4,071,846 9.15 Options forfeited or cancelled (unaudited) (367,675 ) 6.08 Options exercised (unaudited) (1,379,658 ) 1.67 Options outstanding at September 30, 2019 (unaudited) 17,482,443 5.79 438,968
Summary of Estimated Fair Value of Options Granted	The estimated fair value of options granted during the nine months ended September 30, 2019 and 2018 was estimated using the Black-Scholes option-pricing model with the following weighted-average assumptions: Nine Months Ended September 30, 2019 2018 (unaudited) Grant date fair value $ 10.08 $ 6.55 Expected term (in years) 6.06 6.15 Risk-free interest rate 2.4 % 2.7 % Expected volatility 68.0 % 68.9 % Expected dividend yield — —
Summary of Compensation Costs Related to Stock Options and RSUs Included on Statements of Operations	The compensation costs for the three and nine months ended September 30, 2019 and 2018, respectively, related to stock options and RSUs are included on our unaudited condensed statements of operations as follows (in thousands): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (unaudited) Cost of revenue $ 133 $ 97 $ 376 $ 273 Research and development 943 700 2,838 2,168 Sales and marketing 798 620 2,647 2,169 General and administration 1,461 1,136 3,852 3,493 Total share-based compensation expense $ 3,335 $ 2,553 $ 9,713 $ 8,103

Net Loss Per Share Attributab_2

Net Loss Per Share Attributable to Common Shareholders (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Computation of the Basic and Diluted Net Loss Per Share Attributable to Common Shareholders	The following table sets forth the computation of the basic and diluted net loss per share attributable to common shareholders for the three and nine months ended September 30, 2019 and 2018, respectively (in thousands, except shares and per share amounts): Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (unaudited) Net loss $ (13,950 ) $ (8,292 ) $ (47,995 ) $ (33,176 ) Fair value adjustments to redemption value for Series E-1 convertible preferred stock options — (4 ) (964 ) (2 ) Net loss attributable to common shareholders, basic and diluted $ (13,950 ) $ (8,296 ) $ (48,959 ) $ (33,178 ) Weighted-average shares used in computing net loss per share 124,285,686 12,620,010 50,552,389 12,430,535 Net loss per share attributable to common shareholders, basic and diluted $ (0.11 ) $ (0.66 ) $ (0.97 ) $ (2.67 )
Weighted-Average Common Stock Equivalents were Excluded From Calculation of Diluted Net Loss Per Share Attributable to Common Shareholders	The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share attributable to common shareholders for the three and nine months ended September 30, 2019 and 2018, respectively, as they had an anti-dilutive effect: Three Months Ended September 30, Nine Months Ended September 30, 2019 2018 2019 2018 (unaudited) Convertible preferred stock (on as if converted basis) — 92,790,094 61,641,506 92,764,348 Stock options issued and outstanding 17,466,409 14,801,784 17,096,516 14,489,718 Unvested restricted stock units 7,380 — 2,487 — Common stock warrants 56,875 55,032 55,653 55,032 Convertible preferred stock warrant — 56,875 37,708 56,875 Total 17,530,664 107,703,785 78,833,870 107,365,973

Organization and Description _2

Organization and Description of Business - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	Jul. 01, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Subsidiary Or Equity Method Investee [Line Items]
Convertible preferred stock outstanding		0		92,790,094
Initial share reserve		34,578,262
2019 Plan
Subsidiary Or Equity Method Investee [Line Items]
Initial share reserve	15,519,170
Convertible Preferred Stock
Subsidiary Or Equity Method Investee [Line Items]
Convertible preferred stock outstanding		93,039,737	93,039,737	92,790,094	92,790,094	92,790,094	92,656,029
Initial Public Offering
Subsidiary Or Equity Method Investee [Line Items]
Shares issued	17,250,000
Public offering price	$ 20
Net proceeds	$ 315.9
Underwriting discounts, commissions and other costs	24.1
Offering expenses	$ 5

Significant Accounting Polici_4

Significant Accounting Policies - Additional Information (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019USD ($)	Sep. 30, 2019USD ($)Performance_Obligation	Dec. 31, 2018USD ($)
Significant Accounting Policies [Line Items]
Restricted cash	$ 2.1	$ 2.1	$ 0.1
Accounting Standards Update 2016-09
Significant Accounting Policies [Line Items]
Cumulative impact to accumulated deficit		$ 0.1
Sequencing Revenue
Significant Accounting Policies [Line Items]
Number of revenue performance obligations | Performance_Obligation		2
Sequencing Revenue From Coverage Policy
Significant Accounting Policies [Line Items]
Revenue recognized	0.3	$ 1.1
Sequencing Revenue From Test Deliver
Significant Accounting Policies [Line Items]
Revenue recognized	0.1	0.4
Property and Equipment, Net
Significant Accounting Policies [Line Items]
Building costs	23.4	23.4
Additional Paid In Capital
Significant Accounting Policies [Line Items]
Deferred offering costs	$ 5	$ 5

Significant Accounting Polici_5

Significant Accounting Policies - Schedule of Concentrations of Risk Percentage (Details) - Customer Concentration Risk	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Customer A | Revenue
Significant Accounting Policies [Line Items]
Concentration risk, percentage	16.00%	15.70%	11.80%	21.60%
Customer A | Accounts Receivable, Net
Significant Accounting Policies [Line Items]
Concentration risk, percentage			39.60%
Customer B | Revenue
Significant Accounting Policies [Line Items]
Concentration risk, percentage	10.70%
Customer B | Accounts Receivable, Net
Significant Accounting Policies [Line Items]
Concentration risk, percentage					15.10%
Customer C | Revenue
Significant Accounting Policies [Line Items]
Concentration risk, percentage		35.00%		19.10%
Customer C | Accounts Receivable, Net
Significant Accounting Policies [Line Items]
Concentration risk, percentage					13.20%
Genentech, Inc. | Revenue
Significant Accounting Policies [Line Items]
Concentration risk, percentage	43.90%		43.70%

Revenue - Additional Informatio

Revenue - Additional Information (Details) - USD ($)	Sep. 30, 2019	Dec. 18, 2015	Feb. 28, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Disaggregation Of Revenue [Line Items]
Revenue recognized	$ 6,400,000					$ 36,039,000
Revenue from collaboration agreement				$ 26,058,000	$ 17,188,000	60,862,000	$ 38,471,000
Translational Development Agreements
Disaggregation Of Revenue [Line Items]
Term of agreement		4 years
Agreement termination amount receivable		$ 800,000
Eligible payments receivable		2,300,000
Revenue recognized excluding separately negotiated research sequencing contracts				600,000	2,500,000	1,700,000	7,500,000
Translational Development Agreements | Maximum
Disaggregation Of Revenue [Line Items]
Expected revenue through milestone payments		$ 40,000,000
MRD Development Agreements
Disaggregation Of Revenue [Line Items]
Milestone revenue recognized				2,000,000	2,000,000	6,000,000	6,000,000
Revenue recognized				2,300,000	$ 6,100,000	3,100,000	$ 8,000,000
MRD Development Agreements | Maximum
Disaggregation Of Revenue [Line Items]
Additional milestone payment receivable	129,000,000			129,000,000		129,000,000
Genentech Collaboration Agreement
Disaggregation Of Revenue [Line Items]
Non-refundable upfront payments received			$ 300,000,000			300,000,000
Revenue from collaboration agreement				11,400,000		$ 26,200,000
Genentech Collaboration Agreement | Maximum
Disaggregation Of Revenue [Line Items]
Revenue recognition expected period						8 years
Genentech Collaboration Agreement | Maximum | Regulatory Milestones
Disaggregation Of Revenue [Line Items]
Expected revenue through milestone payments	75,000,000			75,000,000		$ 75,000,000
Genentech Collaboration Agreement | Maximum | Development Milestones
Disaggregation Of Revenue [Line Items]
Expected revenue through milestone payments	300,000,000			300,000,000		300,000,000
Genentech Collaboration Agreement | Maximum | Commercial Milestones
Disaggregation Of Revenue [Line Items]
Expected revenue through milestone payments	1,430,000,000			1,430,000,000		1,430,000,000
Genentech Collaboration Agreement | Minimum
Disaggregation Of Revenue [Line Items]
Expected revenue through milestone payments	$ 1,800,000			$ 1,800,000		$ 1,800,000
Revenue recognition expected period						7 years

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Recurring basis - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Financial assets
Total financial assets	$ 720,167	$ 155,986
Financial liabilities
Total financial liabilities		336
Convertible Preferred Stock Warrant Liability
Financial liabilities
Total financial liabilities		336
Level 1
Financial assets
Total financial assets	86,374	45,998
Level 2
Financial assets
Total financial assets	633,793	109,988
Level 3
Financial liabilities
Total financial liabilities		336
Level 3 | Convertible Preferred Stock Warrant Liability
Financial liabilities
Total financial liabilities		336
Money Market Funds
Financial assets
Total financial assets	86,374	45,998
Money Market Funds | Level 1
Financial assets
Total financial assets	86,374	45,998
Commercial Paper
Financial assets
Total financial assets	136,842	16,887
Commercial Paper | Level 2
Financial assets
Total financial assets	136,842	16,887
U.S. Government Debt and Agency Securities
Financial assets
Total financial assets	419,011	85,623
U.S. Government Debt and Agency Securities | Level 2
Financial assets
Total financial assets	419,011	85,623
Corporate Bonds
Financial assets
Total financial assets	77,940	7,478
Corporate Bonds | Level 2
Financial assets
Total financial assets	$ 77,940	$ 7,478

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Details) $ in Millions	9 Months Ended
	Sep. 30, 2019USD ($)
Convertible Preferred Stock Warrant Liability
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other income, net	$ 2.3

Investments - Schedule of Avail

Investments - Schedule of Available-for-sale Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Short-Term Marketable Securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	$ 498,099	$ 110,095
Unrealized Gain	403
Unrealized Loss	(15)	(107)
Estimated Fair Value	498,487	109,988
Long-Term Marketable Securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	135,122
Unrealized Gain	207
Unrealized Loss	(23)
Estimated Fair Value	135,306
Commercial Paper | Short-Term Marketable Securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	136,843	16,887
Estimated Fair Value	136,843	16,887
U.S. Government Debt and Agency Securities | Short-Term Marketable Securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	331,770	85,722
Unrealized Gain	354
Unrealized Loss	(15)	(99)
Estimated Fair Value	332,109	85,623
U.S. Government Debt and Agency Securities | Long-Term Marketable Securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	86,813
Unrealized Gain	112
Unrealized Loss	(23)
Estimated Fair Value	86,902
Corporate Bonds | Short-Term Marketable Securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	29,486	7,486
Unrealized Gain	49
Unrealized Loss		(8)
Estimated Fair Value	29,535	$ 7,478
Corporate Bonds | Long-Term Marketable Securities
Schedule of Available-for-Sale Securities [Line Items]
Amortized Cost	48,309
Unrealized Gain	95
Estimated Fair Value	$ 48,404

Investments - Schedule of Gross

Investments - Schedule of Gross Unrealized Holding Losses and Fair Value for Investments in Unrealized Loss Position (Details) $ in Thousands	Sep. 30, 2019USD ($)
Schedule of Available-for-Sale Securities [Line Items]
Less than 12 months, Fair value	$ 53,975
Less than 12 months, Unrealized loss	(38)
U.S. Government Debt and Agency Securities
Schedule of Available-for-Sale Securities [Line Items]
Less than 12 months, Fair value	53,975
Less than 12 months, Unrealized loss	$ (38)

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Additional Information (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018	Dec. 31, 2015
Goodwill [Line Items]
Goodwill	$ 118,972,000	$ 118,972,000	$ 0
Purchased Intellectual Property
Goodwill [Line Items]
Amortization period of intangible assets	7 years 3 months 18 days

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Summary of Intangible Assets Subject to Amortization (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 20,325	$ 20,325
Accumulated Amortization	(7,969)	(6,699)
Net Carrying Amount	12,356	13,626
Acquired Developed Technology
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	20,000	20,000
Accumulated Amortization	(7,882)	(6,636)
Net Carrying Amount	12,118	13,364
Purchased Intellectual Property
Finite Lived Intangible Assets [Line Items]
Gross Carrying Amount	325	325
Accumulated Amortization	(87)	(63)
Net Carrying Amount	$ 238	$ 262

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Schedule of Future Amortization Expense for Intangible Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Goodwill And Intangible Assets Disclosure [Abstract]
2019	$ 428
2020	1,698
2021	1,698
2022	1,698
2023	1,698
Thereafter	5,136
Net Carrying Amount	$ 12,356	$ 13,626

Deferred Revenue - Schedule of

Deferred Revenue - Schedule of Deferred Revenue by Revenue Classification (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current deferred revenue
Total current deferred revenue	$ 61,269	$ 12,695
Non-current deferred revenue
Total non-current deferred revenue	228,339	704
Total current and non-current deferred revenue	289,608	13,399
Sequencing Revenue
Current deferred revenue
Total current deferred revenue	12,419	11,238
Non-current deferred revenue
Total non-current deferred revenue	1,195	516
Development Revenue
Current deferred revenue
Total current deferred revenue	48,850	1,457
Non-current deferred revenue
Total non-current deferred revenue	$ 227,144	$ 188

Deferred Revenue - Additional I

Deferred Revenue - Additional Information (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Disaggregation Of Revenue [Line Items]
Current deferred revenue	$ 61,269	$ 61,269	$ 12,695
Deferred revenue, less current portion	228,339	228,339	704
Revenue recognized	6,400	36,039
Development Revenue
Disaggregation Of Revenue [Line Items]
Current deferred revenue	48,850	48,850	1,457
Deferred revenue, less current portion	227,144	227,144	188
Development Revenue | Genentech, Inc.
Disaggregation Of Revenue [Line Items]
Current deferred revenue	47,400	47,400
Deferred revenue, less current portion	226,400	226,400
Sequencing Revenue
Disaggregation Of Revenue [Line Items]
Current deferred revenue	12,419	12,419	11,238
Deferred revenue, less current portion	$ 1,195	1,195	$ 516
Revenue recognized		$ 1,500

Deferred Revenue - Additional_2

Deferred Revenue - Additional Information (Details1) - Genentech, Inc. - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date: 2019-10-01	Sep. 30, 2019
Minimum
Disaggregation Of Revenue [Line Items]
Deferred revenue, expected to be recognized	12 months
Maximum
Disaggregation Of Revenue [Line Items]
Deferred revenue, expected to be recognized	8 years

Deferred Revenue - Schedule o_2

Deferred Revenue - Schedule of Changes in Deferred Revenue (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2019
Revenue From Contract With Customer [Abstract]
Deferred revenue balance at December 31, 2018		$ 13,399
Additions to deferred revenue during the period (unaudited)		312,248
Revenue recognized during the period (unaudited)	$ (6,400)	(36,039)
Deferred revenue balance at September 30, 2019 (unaudited)	$ 289,608	$ 289,608

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Details) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2019USD ($)ft²	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)	Sep. 30, 2018USD ($)
Commitments And Contingencies Disclosure [Abstract]
Lease expiration date	Mar. 31, 2024
Number of square feet to-be-constructed | ft²	100,000
Lessee operating lease, rent obligations to commence period	10 months
Lessee, operating lease, term of contract	142 months
Lessee, operating lease, option to extend	Rent obligations commence 10 months thereafter, and the lease term ends 142 months from the date rent commences, subject to our option to twice extend the lease for five years.
Lessee, Operating Lease, Existence of Option to Extend [true false]	true
Lessee, operating lease, extended term of contract	5 years
Landlord contribution for leasehold improvements	$ 20
Letter of credit	$ 2.1
Lease term description				The lease term is through March 2026 and provides for one five-year option.
Payments for tenant improvements				$ 2.4
Rent expenses		$ 1.3	$ 1.1	$ 3.6	$ 2.9

Commitments and Contingencies_2

Commitments and Contingencies - Schedule of Future Minimum Lease Payments Under Operating Leases (Details) $ in Thousands	Sep. 30, 2019USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2019	$ 901
2020	3,963
2021	6,745
2022	10,681
2023	10,985
Thereafter	107,570
Total future minimum lease payments	$ 140,845

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Details)	Jul. 01, 2019shares	Jun. 30, 2019shares	Sep. 30, 2019$ / sharesshares	Sep. 30, 2019Vote$ / sharesshares	Dec. 31, 2014$ / sharesshares	Dec. 31, 2018$ / sharesshares	Sep. 30, 2018shares	Jun. 30, 2018shares	Dec. 31, 2017shares
Class Of Stock [Line Items]
Convertible preferred stock outstanding			0	0		92,790,094
Preferred stock, shares authorized			10,000,000	10,000,000		0
Preferred stock, par value | $ / shares			$ 0.0001	$ 0.0001		$ 0.0001
Preferred stock, shares outstanding			0	0		0
Common stock authorized			340,000,000	340,000,000		131,000,000
Common stock par value | $ / shares			$ 0.0001	$ 0.0001		$ 0.0001
Common stock voting rights description				Holders of our common stock are entitled to one vote for each share of common stock held
Number of vote for each share | Vote				1
Common stock outstanding			124,316,080	124,316,080		12,841,536
Warrants issued to purchase stock			56,875	56,875
Common Stock
Class Of Stock [Line Items]
Warrants issued to purchase stock			20,000	20,000
Warrant exercisable term				10 years
Weighted-average exercise price of warrants | $ / shares			$ 0.37	$ 0.37
Exercise price of warrants | $ / shares			$ 0.45	$ 0.45
Stock issued during period, common stock	54,792		54,792	54,792
Common Stock | Maximum
Class Of Stock [Line Items]
Warrants issued to purchase stock			55,032	55,032
Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Warrants issued to purchase stock					56,875
Warrant exercisable term					7 years
Weighted-average exercise price of warrants | $ / shares					$ 2.64
Convertible Preferred Stock
Class Of Stock [Line Items]
Conversion of convertible preferred stock		93,039,737
Convertible preferred stock outstanding		93,039,737	93,039,737	93,039,737		92,790,094	92,790,094	92,790,094	92,656,029

Shareholders' Equity - Summary

Shareholders' Equity - Summary of Reserved Shares of Common Stock (Details)	Sep. 30, 2019shares
Class Of Stock [Line Items]
Total shares of common stock reserved for future issuance	34,578,262
Exercise of Outstanding Common Stock Options and Vesting of Outstanding Common Restricted Stock Units Granted
Class Of Stock [Line Items]
Total shares of common stock reserved for future issuance	17,495,253
Grant | 2019 Plan
Class Of Stock [Line Items]
Total shares of common stock reserved for future issuance	15,474,217
Grant | Employee Stock Purchase Plan
Class Of Stock [Line Items]
Total shares of common stock reserved for future issuance	1,551,917
Conversion of Common Stock Warrant
Class Of Stock [Line Items]
Total shares of common stock reserved for future issuance	56,875

Equity Incentive Plans - Additi

Equity Incentive Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Jul. 01, 2019	Dec. 31, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Initial share reserve	34,578,262		34,578,262
Share-based compensation expense	$ 3,335	$ 2,553	$ 9,713	$ 8,103
Unrecognized share-based compensation expense related to unvested stock options	34,500		$ 34,500
Unrecognized share-based compensation expense related to unvested stock options, weighted-average period for recognition			3 years 21 days
Option Valuation Model
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Expected dividend yield			0.00%
Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized share-based compensation expense related to unvested stock options, weighted-average period for recognition			8 months 23 days
Unrecognized share-based compensation expense related to unvested RSUs	$ 300		$ 300
Sequenta 2008 Stock Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future issuance	0		0
2009 Equity Incentive Plan | Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future issuance	0		0
2009 Equity Incentive Plan | Options | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option expiration period			10 years
2019 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares available for future issuance	15,474,217,000		15,474,217,000			6,827,996,000
Initial share reserve					15,519,170
2019 Plan | Options
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Initial share reserve	15,519,170		15,519,170
2019 Plan | Options | Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Option expiration period			10 years
2019 Plan | Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation granted shares			12,810
Weighted-average grant date fair value per share			$ 41.63

Equity Incentive Plans - Summar

Equity Incentive Plans - Summary of Changes in Shares Available for Grant (Details) - 2019 Plan	9 Months Ended
	Sep. 30, 2019shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Shares Available for Grant, Outstanding, Beginning Balance	6,827,996,000
Shares Available for Grant, 2019 Plan reserve (unaudited)	12,363,202,000
Shares Available for Grant, Options and RSUs granted (unaudited)	(4,084,656,000)
Shares Available for Grant, Options and RSUs forfeited or cancelled (unaudited)	367,675,000
Shares Available for Grant, Outstanding, Ending Balance (unaudited)	15,474,217,000

Equity incentive Plans - Summ_2

Equity incentive Plans - Summary of Stock Option Activity Under 2008 Plan 2009 Plan and 2019 Plan (Details) $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)$ / sharesshares	Dec. 31, 2018USD ($)
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Shares Subject to Outstanding Options, Options outstanding, Beginning Balance | shares	15,157,930
Shares Subject to Outstanding Options, Options granted (unaudited) | shares	4,071,846
Shares Subject to Outstanding Options, Options forfeited or cancelled (unaudited) | shares	(367,675)
Shares Subject to Outstanding Options, Options exercised (unaudited) | shares	(1,379,658)
Shares Subject to Outstanding Options, Options outstanding, Ending Balance (unaudited) | shares	17,482,443
Weighted Average Exercise Price per Share, Options outstanding, Beginning Balance | $ / shares	$ 4.52
Weighted Average Exercise Price per Share, Options granted (unaudited) | $ / shares	9.15
Weighted Average Exercise Price per Share, Options forfeited or cancelled (unaudited) | $ / shares	6.08
Weighted Average Exercise Price per Share, Options exercised (unaudited) | $ / shares	1.67
Weighted Average Exercise Price per Share, Options outstanding, Ending Balance (unaudited) | $ / shares	$ 5.79
Aggregate Intrinsic Value, Option outstanding | $	$ 438,968	$ 41,690

Equity Incentive Plans - Summ_3

Equity Incentive Plans - Summary of Estimated Fair Value of Options Granted (Details) - $ / shares	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Grant date fair value	$ 10.08	$ 6.55
Expected term (in years)	6 years 21 days	6 years 1 month 24 days
Risk-free interest rate	2.40%	2.70%
Expected volatility	68.00%	68.90%

Equity incentive Plans - Summ_4

Equity incentive Plans - Summary of Compensation Costs Related to Stock Options and RSUS Included on Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 3,335	$ 2,553	$ 9,713	$ 8,103
Cost of Revenue
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	133	97	376	273
Research and Development
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	943	700	2,838	2,168
Sales and Marketing
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	798	620	2,647	2,169
General and Administration
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share-based compensation expense	$ 1,461	$ 1,136	$ 3,852	$ 3,493

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Shareholders - Computation of the Basic and Diluted Net Loss Per Share Attributable to Common Shareholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net loss	$ (13,950)	$ (8,292)	$ (47,995)	$ (33,176)
Fair value adjustments to redemption value for Series E-1 convertible preferred stock options		(4)	(964)	(2)
Net loss attributable to common shareholders, basic and diluted	$ (13,950)	$ (8,296)	$ (48,959)	$ (33,178)
Weighted-average shares used in computing net loss per share attributable to common shareholders, basic and diluted	124,285,686	12,620,010	50,552,389	12,430,535
Net loss per share attributable to common shareholders, basic and diluted	$ (0.11)	$ (0.66)	$ (0.97)	$ (2.67)
Series E-1 Convertible Preferred Stock
Fair value adjustments to redemption value for Series E-1 convertible preferred stock options		$ (4)	$ (964)	$ (2)

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Shareholders - Weighted-Average Common Stock Equivalents were Excluded From Calculation of Diluted Net Loss Per Share Attributable to Common Shareholders (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	17,530,664	107,703,785	78,833,870	107,365,973
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities		92,790,094	61,641,506	92,764,348
Options
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	17,466,409	14,801,784	17,096,516	14,489,718
Unvested Restricted Stock Units
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	7,380		2,487
Common Stock Warrants
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities	56,875	55,032	55,653	55,032
Convertible Preferred Stock Warrant
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Antidilutive securities		56,875	37,708	56,875