Natera (NTRA) 10-K 25 Feb 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Feb. 18, 2022	Jun. 30, 2021
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Document Period End Date	Dec. 31, 2021
Entity File Number	001-37478
Entity Registrant Name	NATERA, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	01-0894487
Entity Address, Address Line One	13011 McCallen Pass
Entity Address, Address Line Two	Building A Suite 100
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78753
City Area Code	650
Local Phone Number	249-9090
Title of 12(b) Security	Common Stock, par value $0.0001 per share
Trading Symbol	NTRA
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 9,330
Entity Common Stock, Shares Outstanding		95,470,898
Entity Central Index Key	0001604821
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false
Auditor Name	Ernst & Young LLP
Auditor Location	Redwood City, California
Auditor Firm ID	42

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 84,386	$ 48,668
Restricted cash	228	187
Short-term investments	829,896	688,606
Accounts receivable, net of allowance of $2,429 in 2021 and $3,080 in 2020	122,074	78,565
Inventory	26,909	20,031
Prepaid expenses and other current assets, net	29,645	26,606
Total current assets	1,093,138	862,663
Property and equipment, net	65,516	33,348
Operating lease right-of-use assets	59,013	21,399
Other assets	18,820	14,743
Total assets	1,236,487	932,153
Current liabilities:
Accounts payable	27,206	8,096
Accrued compensation	40,941	30,371
Other accrued liabilities	93,353	60,407
Deferred revenue, current portion	7,404	50,125
Short-term debt financing	50,052	50,054
Total current liabilities	218,956	199,053
Long-term debt financing	280,394	202,493
Deferred revenue, long-term portion	21,318	22,805
Operating lease liabilities, long-term portion	61,036	21,246
Other long-term liabilities	1,479	320
Total liabilities	583,183	445,917
Commitments and contingencies (Note 8)
Stockholders' equity:
Common stock, $0.0001 par value: 750,000 shares authorized at December 31, 2021 and 2020, respectively; 95,140 and 86,223 shares issued and outstanding at December 31, 2021 and 2020, respectively	10	9
Additional paid in capital	2,050,417	1,411,286
Accumulated deficit	(1,394,836)	(929,318)
Accumulated other comprehensive gain (loss)	(2,287)	4,259
Total stockholders' equity	653,304	486,236
Total liabilities and stockholders' equity	$ 1,236,487	$ 932,153

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Consolidated Balance Sheets
Allowances on accounts receivable	$ 2,429	$ 3,080
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares issued	95,140,000	86,223,000
Common stock, shares outstanding	95,140,000	86,223,000

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues
Total revenues	$ 625,486	$ 391,005	$ 302,328
Cost and expenses
Research and development	264,208	100,035	51,357
Selling, general and administrative	511,034	303,627	206,176
Gain from disposal of business			(14,388)
Total cost and expenses	1,093,660	607,282	418,615
Loss from operations	(468,174)	(216,277)	(116,287)
Interest expense	(8,305)	(15,082)	(10,693)
Interest and other income, net	5,381	7,562	4,152
Loss on debt extinguishment		(5,848)
Loss before income taxes	(471,098)	(229,645)	(122,828)
Income tax expense	(618)	(98)	(1,999)
Net loss	(471,716)	(229,743)	(124,827)
Unrealized gain (loss) on available-for-sale securities, net of tax	(6,546)	3,340	1,471
Comprehensive loss	$ (478,262)	$ (226,403)	$ (123,356)
Net loss per share (Note 14):
Basic (in dollars per share)	$ (5.21)	$ (2.84)	$ (1.79)
Diluted (in dollars per share)	$ (5.21)	$ (2.84)	$ (1.79)
Weighted-average number of shares used in computing basic and diluted net loss per share:
Basic (in shares)	90,558	81,011	69,555
Diluted (in shares)	90,558	81,011	69,555
Product
Revenues
Total revenues	$ 567,149	$ 367,211	$ 269,881
Cost and expenses
Cost of revenues	302,663	185,865	162,604
Licensing and other
Revenues
Total revenues	58,337	23,794	32,447
Cost and expenses
Cost of revenues	$ 15,755	$ 17,755	$ 12,866

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Total
Balance at Dec. 31, 2018	$ 7	$ 607,236	$ (552)	$ (574,529)	$ 32,162
Balance (in shares) at Dec. 31, 2018	62,083,000
Issuance of common stock upon exercise of stock options		13,041			13,041
Issuance of common stock upon exercise of stock options (in shares)	2,464,000
Issuance of common stock under employee stock purchase plan		4,323			4,323
Issuance of common stock under employee stock purchase plan (in shares)	268,000
Issuance of common stock to Orbimed		507			507
Issuance of common stock to Orbimed (in shares)	25,000
Vesting of restricted stock (in shares)	541,000
Stock based compensation		28,624			28,624
Unrealized (loss) gain on available-for-sale securities			1,471		1,471
Cumulative-effect adjustment upon adoption		(185)		185
Issuance/Sale of common stock for offering, net	$ 1	323,409			323,410
Issuance/Sale of common stock for offering, net (in shares)	12,624,000
Net loss				(124,827)	(124,827)
Balance at Dec. 31, 2019	$ 8	976,955	919	(699,171)	278,711
Balance (in shares) at Dec. 31, 2019	78,005,000
Issuance of common stock upon exercise of stock options		23,524			23,524
Issuance of common stock upon exercise of stock options (in shares)	2,092,000
Issuance of common stock under employee stock purchase plan		7,114			7,114
Issuance of common stock under employee stock purchase plan (in shares)	234,000
Vesting of restricted stock (in shares)	1,100,000
Stock based compensation		50,171			50,171
Unrealized (loss) gain on available-for-sale securities			3,340		3,340
Cumulative-effect adjustment upon adoption				(404)	(404)
Equity component of Convertible Notes, net		82,873			82,873
Issuance/Sale of common stock for offering, net	$ 1	270,649			270,650
Issuance/Sale of common stock for offering, net (in shares)	4,792,000
Net loss				(229,743)	(229,743)
Balance at Dec. 31, 2020	$ 9	1,411,286	4,259	(929,318)	$ 486,236
Balance (in shares) at Dec. 31, 2020	86,223,000				86,223,000
Issuance of common stock upon exercise of stock options		11,816			$ 11,816
Issuance of common stock upon exercise of stock options (in shares)	1,165,000
Issuance of common stock under employee stock purchase plan		13,550			13,550
Issuance of common stock under employee stock purchase plan (in shares)	186,000
Vesting of restricted stock (in shares)	2,117,000
Stock based compensation		115,219			115,219
Unrealized (loss) gain on available-for-sale securities			(6,546)		(6,546)
Cumulative-effect adjustment upon adoption		(82,876)		6,198	(76,678)
Issuance/Sale of common stock for offering, net	$ 1	550,821			550,822
Issuance/Sale of common stock for offering, net (in shares)	5,175,000
Issuance of common stock for IPR&D acquisition		30,601			30,601
Issuance of common stock for IPR&D acquisition (in shares)	274,000
Net loss				(471,716)	(471,716)
Balance at Dec. 31, 2021	$ 10	$ 2,050,417	$ (2,287)	$ (1,394,836)	$ 653,304
Balance (in shares) at Dec. 31, 2021	95,140,000				95,140,000

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities:
Net loss	$ (471,716)	$ (229,743)	$ (124,827)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	11,254	8,613	7,730
Expensed in-process research and development	35,604
Non-cash lease expense	10,926	7,834	7,748
Impairment of assets	0		1,671
Stock-based compensation	115,219	50,171	28,624
Inventory reserve adjustments	628	(163)	321
Premium amortization and discount accretion on investment securities	7,814	5,761	945
Loss on investments	(46)	(105)	(16)
Unrealized losses on investment securities	(11)
Amortization of debt discount and issuance cost	1,227	149	457
Other non-cash benefits (charges)	94	(149)	(51)
Gain on disposal of business			(14,388)
Provision for credit losses	(156)	1,354	1,141
Loss on debt extinguishment		5,848
Accretion of Convertible Note		7,048
Changes in operating assets and liabilities:
Accounts receivable	(43,353)	(25,831)	2,418
Inventory	(7,506)	(7,474)	917
Prepaid expenses and other current assets	(10,545)	(23,386)	(13,956)
Other assets	(2,933)	(60)	(9,099)
Accounts payable	19,222	(118)	(6,262)
Accrued compensation	10,569	14,284	3,419
Other accrued liabilities	32,682	10,340	8,606
Deferred revenue	(44,209)	(6,895)	40,848
Other long-term liabilities		10	310
Net cash used in operating activities	(335,236)	(182,512)	(63,444)
Investing activities:
Purchases of investments	(876,095)	(685,239)	(446,626)
Proceeds from sale of investments	187,580	30,067	1,666
Proceeds from maturity of investments	532,910	343,315	173,900
Net proceeds from disposal of business			9,675
Purchases of property and equipment, net	(41,030)	(19,604)	(4,968)
Cash paid for acquisition of an asset	(8,558)
Net cash used in investing activities	(205,193)	(331,461)	(266,353)
Financing activities:
Proceeds from exercise of stock options	11,816	23,524	13,041
Proceeds from issuance of common stock under employee stock purchase plan	13,550	7,114	4,323
Proceeds from Convertible Note, net of issuance costs		278,316
Loan payment		(78,757)
Proceeds from public offering, net of issuance costs	550,822	270,650	323,410
Net cash provided by financing activities	576,188	500,847	340,774
Net increase (decrease) in cash equivalents and restricted cash	35,759	(13,126)	10,977
Beginning - cash equivalents & restricted cash	48,855	61,981	51,004
Ending - cash equivalents and restricted cash	84,614	48,855	61,981
Supplemental disclosure of cash flow information:
Cash paid for income taxes	283	67	2,154
Cash paid for interest	7,077	3,296	12,455
Non-cash investing and financing activities:
Purchases of property and equipment in accounts payable and accruals	$ 5,173	$ 2,781	$ 3,706

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2021
Description of Business
Description of Business	1 . Description of Business ​ Natera, Inc. (the “Company”) was formed in the state of California as Gene Security Network, LLC in November 2003 and incorporated in the state of Delaware in January 2007. The Company is a diagnostics company with proprietary molecular and bioinformatics technology that it is applying to change the management of disease worldwide. The Company’s cell-free DNA (“cfDNA”) technology combines its novel molecular assays, which reliably measure many informative regions across the genome from samples as small as a single cell, with its statistical algorithms which incorporate data available from the broader scientific community to identify genetic variations covering a wide range of serious conditions with high accuracy and coverage. The Company’s technology has been proven clinically and commercially in the women’s health space, in which it develops and commercializes non- or minimally-invasive tests to evaluate risk for, and thereby enable early detection of, a wide range of genetic conditions, such as Down syndrome. The Company is now translating its success in women’s health and applying its core technology to the oncology market, in which it is commercializing a personalized blood-based DNA test to detect molecular residual disease and monitor disease recurrence, as well as to the organ health market, initially with a test to assess kidney transplants for rejection. The Company operates laboratories certified under the Clinical Laboratory Improvement Amendments ("CLIA") providing a host of cell-free DNA-based molecular testing services. The Company determines its operating segments based on the way it organizes its business to make operating decisions and assess performance. The Company operates The Company's product offerings include its Panorama Non-Invasive Prenatal Test ("NIPT") that screens for chromosomal abnormalities of a fetus as well as in twin pregnancies, typically with a blood draw from the mother; Vistara, a single-gene mutations screening test performed to identify single-gene disorders; Horizon Carrier Screening ("HCS") to determine carrier status for a large number of severe genetic diseases that could be passed on to the carrier’s children; Spectrum Pre-implantation Genetics (“Spectrum”) to evaluate embryos to identify chromosomal anomalies or inherited genetic conditions to improve the chances of a healthy pregnancy during an in vitro fertilization ("IVF") cycle; Anora Miscarriage Test (“Anora”) to rapidly and extensively analyze fetal chromosomes to understand the cause of miscarriage; Non-Invasive Paternity Testing (“PAT”), which is exclusively marketed and sold by a licensee from whom the Company receives a royalty; Signatera, which detects circulating tumor DNA in patients previously diagnosed with cancer to assess molecular residual disease and monitor for recurrence; and Prospera, to assess organ transplant rejection. All testing is available principally in the United States. The Company also offers its Panorama test to customers outside of the United States, primarily in Europe. The Company also offers Constellation, a cloud-based software platform that enables laboratory customers to gain access through the cloud to the Company’s algorithms and bioinformatics in order to validate and launch their own tests based on the Company’s technology. Through the third quarter of 2019, the Company offered Evercord for the collection and storage of newborn cord blood and cord tissue units, which was sold in the third quarter of 2019 to a third-party buyer.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Summary of Significant Accounting Policies
Summary of Significant Accounting Policies	2 Summary of Significant Accounting Policies ​ Basis of Presentation ​ The accompanying consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”). ​ Liquidity Matters ​ The Company has incurred net losses since its inception and anticipates net losses and negative operating cash flows for the near future. The Company had a net loss of $471.7 million for the year ended December 31, 2021 and an accumulated deficit of $1.4 billion as of December 31, 2021. As of December 31, 2021, the Company had $84.6 million in cash, cash equivalents, and restricted cash, $829.9 million in marketable securities, $50.1 million of outstanding balance of the Credit Line (as defined in Note 10, Debt) including accrued interest, and $287.5 million outstanding principal balance of its 2.25% Convertible Senior Notes (the “Convertible Notes”). In April 2020, the Company used a portion of the net proceeds from the offering of the Convertible Notes to repay its obligations under its 2017 Term Loan with OrbiMed. ​ While the Company has introduced multiple products that are generating revenues, these revenues have not been sufficient to fund all operations and business plans. Accordingly, the Company has funded the portion of its operating costs and business plans that exceed revenues through a combination of equity issuances, debt issuances, and other financings. The Company continues to invest in the development and commercialization of its existing and future products and, consequently, it will need to generate additional revenues to achieve future profitability and may need to raise additional equity or debt financing. If the Company raises additional funds by issuing equity securities, its stockholders will experience dilution. Additional debt financing, if available, may involve covenants restricting its operations or its ability to incur additional debt. Any additional debt financing or additional equity that the Company raises may contain terms that are not favorable to it or its stockholders and requires significant debt service payments, which diverts resources from other activities. Additional financing may not be available when necessary, or in amounts or on terms acceptable to the Company. If the Company is unable to obtain additional financing, it may be required to delay or slow its investment in the development and commercialization of its products and significantly scale back its business and operations. On September 10, 2021, the Company entered into an agreement with a third party for an asset acquisition where the acquired asset was in-process research and development primarily in exchange for an equity consideration payment. In addition, pursuant to the agreement, certain employees of the third party became employees of the Company. The third party was a biotechnology company focused on oncology. The total upfront acquisition consideration amounts to $35.6 million composed of the issuance of 276,346 shares of the Company's common stock with a fair value of $30.9 million, approximately $3.9 million of cash consideration, assumed net liabilities of $0.2 million, as well as $0.6 million of acquisition related legal and accounting costs directly attributable to the acquisition of the asset. The Company accounted for the transaction as an asset acquisition as substantially all of the estimated fair value of the gross assets acquired was concentrated in a single identified in-process research and development asset (“IPR&D”) thus satisfying the requirements of the screen test in ASU 2017-01. The estimated fair value of the acquired workforce was not significant. The Company concluded the acquired IPR&D has no alternative-future use and accordingly expensed approximately $35.6 million, on the day the transaction closed as research and development expense, which is reflected in its consolidated statement of operations. Further, additional consideration aggregating up to approximately $35.0 million may be paid in an estimated 269,547 of additional shares, consistent with the registration statement filed with the SEC on September 10, 2021, that are potentially issuable to legacy shareholders of this third party upon the achievement of defined milestones relating to product development, commercial launch and continued employment of certain selling shareholders, each of which will be revalued at each reporting date and amount of compensation expense will be adjusted accordingly. The Company assessed these milestones as probable as of September 30, 2021 and December 31, 2021. As achievement of all milestones is contingent upon the continued employment of certain selling shareholders, the Company accounted for the consideration related to all of the milestones as compensation expenses and recognized these expenses ratably over the estimated performance period of 24 months, to approximately August 2023. ​ In April 2019, the Company completed an underwritten equity offering and sold 6,052,631 shares of its common stock at a price of $19 per share to the public. Before offering expenses of $0.6 million, the Company received proceeds of $108.1 million net of the underwriting discount. In October 2019, the Company completed another underwritten equity offering and sold 6,571,428 shares of its common stock at a price of $35 per share to the public. Before offering expenses of $0.4 million, the Company received proceeds of $216.2 million net of the underwriting discount. In September 2020, the Company completed an additional underwritten equity offering and sold 4,791,665 shares of its common stock at a price of $60.00 per share to the public. Before offering expenses of $0.3 million, the Company received proceeds of $271.0 million net of the underwriting discount. In July 2021, the Company completed an underwritten equity offering and sold 5,175,000 shares of its common stock at a price of $113 per share to the public. Before offering expenses of $0.4 million, the Company received proceeds of $551.2 million net of the underwriting discount. Based on the Company’s current business plan, the Company believes that its existing cash and marketable securities will be sufficient to meet its anticipated cash requirements for at least 12 months after February 24, 2022. ​ Principles of Consolidation ​ The accompanying consolidated financial statements include all the accounts of the Company and its subsidiaries. The Company established a subsidiary that operates in the state of Texas to support the Company’s laboratory and operational functions. The Company established a subsidiary that operates in Canada following the acquisition of the IPR&D asset, which includes a lease for the laboratory space located in Canada. All intercompany balances and transactions have been eliminated. ​ Use of Estimates ​ ​ Revenue ​ ​ ​ Stock-based compensation ​ ​ ​ requisite service period in which the awards are expected to vest and forfeitures are estimated based on historical trends at the time of grant and revised as necessary. Stock option awards that include a service condition and a performance condition are considered expected to vest when the performance condition is probable of being met. The Black-Scholes model considers several variables and assumptions in estimating the fair value of stock-based awards. These variables include the per share fair value of the underlying common stock, exercise price, expected term, risk-free interest rate, expected annual dividend yield and the expected stock price volatility over the expected term. For all stock options granted, we calculate the expected term using the simplified method for “plain vanilla” stock option awards. We determine expected volatility using the historical volatility of the stock price of similar publicly traded peer companies. The risk-free interest rate is based on the yield available on U.S. Treasury zero-coupon issues similar in duration to the expected term of the equity-settled award. ​ ​ ​ ​ Income Taxes ​ Income Taxes Income Taxes ​ Allowance for doubtful accounts ​ ​ Financial Instruments—Credit Losses ​ Inventory ​ and scrapped inventory. Any write-down of inventory to net realizable value establishes a new cost basis and will be maintained even if certain circumstances suggest the inventory is recoverable in subsequent periods. Costs associated with the write-down of inventory are recorded to cost of revenue on our consolidated statements of operations. The Company makes assumptions about future demand, market conditions and the release of new products that may supersede older products. However, if actual market conditions are less favorable than anticipated, additional inventory write-downs may be required. ​ Investments and financial instruments ​ ​ Right-of-use assets ​ ​ Property and equipment ​ three years ​ Other accrued liabilities ​ ​ Cash and Cash Equivalents ​ Cash and cash equivalents consist of cash and money market deposits with financial institutions. ​ Restricted Cash ​ Restricted cash is currently presented as a separate line item in the Company’s balance sheet. In the statements of cash flows, it is included together with cash and cash equivalents and considered as part of the total ending cash balance. The following is the reconciliation between how restricted cash is presented in the balance sheet and the statements of cash flows for all periods presented: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 ​ ​ (in thousands) Cash and cash equivalents in balance sheet ​ $ 84,386 ​ $ 48,668 Restricted cash, current portion in balance sheet ​ ​ 228 ​ ​ 187 Total cash, cash equivalents and restricted cash in statements of cash flows ​ $ 84,614 ​ $ 48,855 ​ Investments Investments consist primarily of debt securities such as U.S. Treasuries, U.S. agency and municipal bonds. Management determines the appropriate classification of securities at the time of purchase and re-evaluates such determination at each balance sheet date. The Company generally classifies its entire investment portfolio as available-for-sale. The Company views its available-for-sale portfolio as available for use in current operations. Accordingly, the Company classifies all investments as short-term, irrespective of maturity date. Available-for-sale securities are carried at fair value, with unrealized gains and losses reported in accumulated other comprehensive income (loss), which is a separate component of stockholders’ equity. ​ On December 6, 2021, the Company participated along with certain other investors in the series B financing of MyOme, Inc. (“MyOme”), and purchased preferred shares and warrants in exchange for approximately $4.0 million cash payment. Matthew Rabinowitz is the Chairman of the board of directors and Co-Founder of both the Company and MyOme. The Company’s investment in MyOme is recorded at cost and will be evaluated for impairment at the end of each reporting period. ​ Fair Value ​ The Company discloses the fair value of financial instruments for financial assets and liabilities for which the value is practicable to estimate. Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price). ​ Risk and Uncertainties ​ The Company is subject to risks and uncertainties as a result of the COVID-19 pandemic. The extent of the impact of the COVID-19 pandemic on the Company's business is highly uncertain and difficult to predict, and the full extent and duration of the impact of the COVID 19 pandemic on our business, our operations, and the global economy as a whole is not yet known. While the Company’s test volumes as well as overall average selling prices increased in the year ended December 31, 2021 compared to the year ended December 31, 2020, the Company cannot predict the potential nature, magnitude and duration of the effects of the COVID-19 pandemic on the macroeconomic environment. Financial instruments that potentially subject the Company to credit risk consist of cash, accounts receivable and investments. The Company limits its exposure to credit loss by placing its cash in financial institutions with high credit ratings. The Company's cash may consist of deposits held with banks that may at times exceed federally insured limits. The Company performs evaluations of the relative credit standing of these financial institutions and limits the amount of credit exposure with any one institution. The Company performs evaluations of financial conditions for insurance carriers, patients, clinics and laboratory partners and generally does not require collateral to support credit sales. For the years ended December 31, 2021, 2020, and 2019, there were no customers exceeding 10% of total revenues on an individual basis. As of December 31, 2021 and 2020, there were no customers with an outstanding balance exceeding 10% of net accounts receivable. ​ Credit Losses ​ Trade accounts receivable and other receivables. ​ The following is a roll-forward of the allowances for credit losses related to trade accounts receivable and other receivables for the year ended December 31, 2021: ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ ​ (in thousands) Beginning balance ​ $ 4,220 Provision for credit losses ​ ​ (156) Write-offs ​ ​ (1,635) Total ​ $ 2,429 ​ Available-for-sale debt securities. The amended guidance from ASU 2016-13 requires the measurement of expected credit losses for available-for-sale debt securities held at the reporting date over the remaining life based on historical experience, current conditions, and reasonable and supportable forecasts. The Company evaluated its investment portfolio under the new available-for-sale debt securities impairment model guidance. The vast majority of the Company’s investment portfolio are low risk, investment grade securities. ​ Revenue Recognition ​ The Company adopted the new revenue recognition guidance, ASC 606, beginning January 1, 2018 on a full retrospective basis. ASC 606 mandates revenue recognition to be evaluated using the following five steps: ​ ● Identification of a contract, or contracts, with a customer; ● Identification of the performance obligations in the contract; ● Determination of the transaction price; ● Allocation of the transaction price to the performance obligations in the contract; and ● Revenue recognition when, or as, the performance obligations are satisfied ​ Revenue Recognition, ​ Cost of Product Revenues ​ The components of our cost of product revenues are material and service costs, impairment charges associated with testing equipment, personnel costs, including stock-based compensation expense, equipment and infrastructure expenses associated with testing samples, electronic medical records, order and delivery systems, shipping charges to transport samples, costs incurred from third party test processing fees, and allocated overhead such as rent, information technology costs, equipment depreciation and utilities. Costs associated with Whole Exome Sequencing (“WES”) are also included, as well as labor costs, relating to our Signatera CLIA offering. Costs associated with performing tests are recorded when the test is accessioned. We expect cost of product revenues in absolute dollars to increase as the number of tests we perform increases. ​ ​ Cost of Licensing and Other Revenues ​ The components of our cost of licensing and other revenues are material costs associated with test kits sold to Constellation clients, development and support services relating to our Strategic Partnership Agreements, and costs associated with specimens and Whole Exome Sequencing (“WES”), as well as labor costs, relating to our Signatera (RUO) and CDx offering. ​ We consider our cost of licensing and other revenues for the Constellation software platform to be relatively low, and therefore we expect its associated gross margin is higher. We expect our cost of licensing will increase in relation to volume growth. ​ Research and Development ​ The Company records research and development costs in the period incurred. Research and development costs consist of personnel costs, contract services, cost of materials utilized in performing tests, costs of clinical trials and allocated facilities and related overhead expenses. ​ Advertising Costs ​ The Company expenses advertising costs as incurred. The Company incurred advertising costs of $2.2 million, $0.6 million, and $0.2 million for the years ended December 31, 2021, 2020, and 2019, respectively. ​ Product Shipment Costs ​ The Company expenses product shipment costs in cost of product revenues in the accompanying statements of operations. Shipping and handling costs for the years ended December 31, 2021, 2020, and 2019 were $22.0 million, $13.3 million, and $13.3 million, respectively. ​ Income Taxes ​ Income taxes are recorded in accordance with Financial Accounting Standards Board ASC Topic 740, Income Taxes ​ Stock-Based Compensation ​ Stock-based compensation related to stock options and restricted stock units (“RSUs”) granted to the Company’s employees is measured at the grant date based on the fair value of the award. The fair value is recognized as expense over the requisite service period, which is generally the vesting period of the respective awards. No compensation cost is recognized when the requisite service has not been met and the awards are therefore forfeited. ​ For stock options with market conditions, the Company derives the requisite service period using the Monte Carlo simulation model. For stock options and RSUs that vest upon meeting performance conditions or market conditions in combination with performance conditions, the Company derives the requisite service period from the grant date to the date it is probable that the vesting conditions will be met. ​ ​ Capitalized Software Held for Internal Use ​ The Company capitalizes salaries and related costs of employees and consultants who devote time to the development of internal-use software development projects. Capitalization begins during the application development stage, once the preliminary project stage has been completed, which includes successful validation and approval from management. If a project constitutes an enhancement to previously developed software, the Company assesses whether the enhancement is significant and creates additional functionality to the software, thus qualifying the work incurred for capitalization. Once the project is available for general release, capitalization ceases and the Company estimates the useful life of the asset and begins amortization. The Company periodically assesses whether triggering events are present to review internal-use software for impairment. Changes in estimates related to internal-use software would increase or decrease operating expenses or amortization recorded during the reporting period. ​ The Company amortizes its internal-use software over the estimated useful lives of three years. The net book value of capitalized software held for internal use was $2.3 million and $1.7 million as of December 31, 2021 and 2020, respectively. Amortization expense for amounts previously capitalized for the years ended December 31, 2021, 2020, and 2019, was $1.1 million, $1.0 million, and $1.2 million, respectively. ​ Accumulated Other Comprehensive Income (Loss) Comprehensive loss and its components encompass all changes in equity other than those with stockholders, and include net loss, and unrealized gains and losses on available-for-sale marketable securities. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ ​ (in thousands) Beginning balance ​ $ 4,259 ​ $ 919 Net unrealized gains (losses) on available-for-sale securities, net of tax ​ ​ (6,546) ​ ​ 3,340 Ending balance ​ $ (2,287) ​ $ 4,259 ​ ​ ​ ​ ​ ​ ​ ​ Property and Equipment ​ Property and equipment, including purchased and internally developed software, are stated at cost. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, which are generally three five or the remaining term of the lease, whichever is shorter. The Company periodically reviews the depreciable lives assigned to property and equipment placed in service and change the estimates of useful lives to reflect the results of such reviews. ​ Impairment of Long-lived Assets ​ The Company evaluates its long-lived assets for indicators of possible impairment when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. The Company then compares the carrying amounts of the assets with the future net undiscounted cash flows expected to be generated by such asset. Should an impairment exist, the impairment loss would be measured based on the excess carrying value of the asset over the asset’s fair value determined using discounted estimates of future cash flows. ​ Inventory ​ Inventory is valued at the lower of the standard cost, which approximates actual cost, or market. Cost is determined using the first-in, first-out (“FIFO”) method. Inventory consists entirely of supplies, which are consumed when providing its test reports, and therefore does not maintain any finished goods inventory. The Company enters into inventory purchases and commitments so that it can meet future delivery schedules based on forecasted demand for its tests. ​ The Company recorded inventory obsolescence charges totaling $0.9 million, $0.2 million, and $0.3 million, in the years ended December 31, 2021, 2020, and 2019, respectively. ​ Recent Accounting Pronouncements ​ From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “FASB”) under its accounting standard codifications (“ASC”) or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed below, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption. ​ Recently Adopted Accounting Pronouncements ​ Income Taxes Codification Improvements Debt In August 2020, ASU 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40) cumulative effect of the change was recognized as an adjustment to the opening balance of retained earnings at the date of adoption. The comparative information has not been restated and continues to be presented according to accounting standards in effect for those periods. This adjustment was calculated based on the carrying amount of the Convertible Notes as if it had always been treated only as a liability. Further, an adjustment was recorded to the debt discount and issuance costs as if these had always been treated as a contra liability only. Interest expense related to the accretion of the Convertible Notes is no longer recognized. Interest expense for the Convertible Notes for the year ended December 31, 2021 would have been $9.4 million higher without the adoption of ASU 2020-06. As such, net loss from continuing operations attributable to the Company for the year ended December 31, 2021 was $0.10 per common share lower due to the effect of adoption of ASU 2020-06. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ASU 2020-06 ​ January 1, ​ 2020 ​ Adoption Adjustment ​ 2021 ​ (in thousands) Liabilities ​ ​ ​ ​ ​ ​ ​ ​ Outstanding Principal $ 287,500 ​ $ — ​ $ 287,500 Unamortized debt discount and issuance cost ​ (85,007) ​ ​ 76,674 ​ ​ (8,333) Net carrying amount $ 202,493 ​ $ 76,674 ​ $ 279,167 ​ ​ ​ ​ ​ ​ ​ ​ ​ Equity ​ ​ ​ ​ ​ ​ ​ ​ Additional paid-in-capital $ (1,411,286) ​ $ 82,876 ​ $ (1,328,410) Accumulated deficit ​ (929,318) ​ ​ 6,198 ​ ​ (923,120) ​ ​ New Accounting Pronouncements Not Yet Adopted In March 2020, ASU 2020-04, Reference Rate Reform (Topic 848)

Revenue Recognition

Revenue Recognition	12 Months Ended
	Dec. 31, 2021
Revenue Recognition
Revenue Recognition	3. Revenue Recognition ​ ​ Product Revenues ​ Product revenues are derived from contracts with insurance carriers, laboratory partners and patients in connection with sales primarily related to prenatal genetic tests. The Company enters into contracts with insurance carriers with primarily payment terms related to tests provided to the patients who have health insurance coverage. Insurance carriers are considered as third-party payers on behalf of the patients, and the patients are considered as the customers who receive genetic test services. Tests may be billed to insurance carriers, patients, or a combination of insurance carriers and patients. Further, the Company sells tests to a number of domestic and international laboratory partners and identifies the laboratory partners as customers provided that there is a test services agreement between the two parties. ​ A performance obligation represents a promise in a contract to transfer a distinct good or service to a customer, which represents a unit of accounting in accordance with ASC 606. A performance obligation is considered distinct from other obligations in a contract when it provides a benefit to the customer either on its own or together with other resources that are readily available to the customer and is separately identified in the contract. The Company considers a performance obligation satisfied once the Company has transferred control of a good or service to the customer, meaning the customer has the ability to use and obtain the benefit of the good or service. A portion of the consideration should be allocated to each distinct performance obligation and recognized as revenue when, or as, the performance obligation is satisfied. The Company evaluates its contracts with insurance carriers, laboratory partners and patients and identifies the performance obligations in those contracts, which are the delivery of the test results. ​ The total consideration which the Company expects to be entitled to from patients and insurance carriers in exchange for the Company's products is determined based on agreements with insurance carriers, effects of variable consideration, and customary business practices. The transaction price is estimated based on the contractual pricing agreed to with each insurance carrier for each test (CPT code) performed adjusted for variable consideration related to historical percent of cases allowed, historical percent of patient responsibility collected, and historical percent of contract price collected from insurance carriers. The Company uses the expected-value approach of estimating variable consideration. The Company also considers recent trends, past events not expected to recur, and future known changes such as anticipated contractual pricing changes or insurance coverages. For insurance carriers with similar reimbursement characteristics, the Company uses a portfolio approach to estimate the effects of variable consideration. The Company also applies a constraint to the estimated variable consideration when it assesses it is probable that a significant reversal in the amount of cumulative revenue may occur in future periods. The total consideration which the Company expects to be entitled to from lab partners is generally fixed, but can be variable depending on the volume of tests performed, which is estimated using the expected-value approach. For insurance carriers, laboratory partners and patients, the Company allocates the total consideration to a single performance obligation, which is the delivery of the test results to the customers. ​ When assessing the total consideration for insurance carriers and patients, a certain percentage of revenues is further constrained for estimated refunds. ​ The Company generally bills an insurance carrier, a laboratory partner or a patient upon delivery of test results. The Company also bills patients directly for out-of-pocket costs involving co-pays and deductibles that they are responsible for. Tests billed to insurance carriers and directly to patients usually take an average of nine to twelve months to collect payment, and for tests billed to laboratory distribution partners, the average collection cycle takes approximately two to three months. At times, the Company may or may not get reimbursed for the full amount billed. Further, the Company may not get reimbursed at all for tests performed if such tests are not covered under the insurance carrier’s reimbursement policies or the Company is not a qualified provider to the insurance carrier, or if the tests were not previously authorized. Product revenue is recognized in an amount that equals to the total consideration (as described above) at a point in time when the test results are delivered. The Company reserves certain amounts in other accrued liabilities on the balance sheet in anticipation of requests for refunds of payments previously made by insurance carriers, which are accounted for as reductions in product revenues in the statement of operations and comprehensive loss. During the years ended December 31, 2021, 2020, and 2019, $5.7 million, $5.4 million, and $2.4 million, respectively, were released from amounts previously held in reserves in other accrued liabilities and recognized as product revenue. ​ Licensing and Other Revenues ​ The Company recognizes licensing revenues from its cloud-based distribution service offering, Constellation, by granting licenses to its licensees to use certain of the Company’s proprietary intellectual properties and cloud-based software and IVD kits. The Company also recognizes revenues from the Signatera research use only (“RUO”) and CDx offering, the Qiagen LLC, BGI Genomics Co., Ltd., and Foundation Medicine, Inc. agreements. Constellation The laboratory partners with which the Company enters into a licensing arrangement represent the licensees and are identified as customers. The licensees do not have the right to possess the Company’s software, but rather receive professional services through the cloud software. These arrangements often include: (i) the delivery of the services through the cloud software, (ii) the necessary support and training, and (iii) the IVD kits to be consumed as tests are processed. The Company does not consider the software as a service, the support and training as being distinct in the context of such arrangements, and therefore they are combined as a single performance obligation. The software, support and training are delivered simultaneously to the licensees over the term of the arrangement. The Company bills the majority of licensees, who process the tests in their laboratories, a fixed price for each test processed. Licensing revenues are recognized as the performance obligations are satisfied (i.e., upon the delivery of each test) and reported in licensing and other revenues in the statements of operations and comprehensive loss. ​ Signatera Qiagen BGI Genomics In February 2019, the Company entered into a License Agreement with BGI Genomics Co., Ltd. (“BGI Genomics”) to develop, manufacture, and commercialize NGS-based genetic testing assays for clinical and commercial use. The agreement has a term of ten years and expires in February 2029. According to the agreement, the Company is entitled to a total of $50 million, comprised of upfront technology license fees, prepaid royalties relating to future sales of licensed products and performance of assay interpretation services, and milestone payments. During the three months ended June 30, 2019, the Company received $35.6 million, net of withholding taxes, of these amounts. The Company recorded a receivable of $2.5 million upon achieving the first milestone as of June 30, 2019, which was received in January 2021. Also, as required by the agreement with BGI Genomics, in June 2019 the Company prepaid $6.0 million to BGI Genomics for future sequencing services and $4.0 million for future sequencing equipment. These advance payments for equipment and services to be received in future periods aggregating to $10.0 million were recorded in long-term advances on the Balance Sheet. ​ Pursuant to the agreement, the Company licensed its intellectual property and will provide development services. Following completion of development services, the Company will provide assay interpretation services over the term of the agreement. The Company concluded that the license is not a distinct performance obligation as it does not have a stand-alone value to BGI Genomics apart from the related development services. Therefore, license and related development services, for each of the NIPT and Oncology products, represents a single performance obligation. ​ The Company is responsible for granting a license to specified intellectual property and performing certain development activities to customize its genetic testing assays for oncology and NIPT for use with BGI Genomics’ sequencing instruments and proprietary technology platform. Revenue associated with these performance obligations is recognized over time using the input method, based on costs incurred to perform the development services, since the level of costs incurred over time best reflect the transfer of development services. Revenue associated with the assay interpretation services will be recognized upon delivery of these services. Funds received in advance are recorded as deferred revenue and will be recognized as the related services are delivered. The initial transaction price was primarily comprised of license and milestone fees. The Company constrains the estimated variable consideration when it assesses it is probable that a significant reversal in the amount of cumulative revenue recognized may occur in future periods. Certain milestone and license fees were constrained and not included in the transaction price due to the uncertainties of research and development. The Company re-evaluates the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as uncertain events are resolved or other changes in circumstances occur. The allocation of the transaction price was performed based on standalone selling prices, which are based on estimated amounts that the Company would charge for a performance obligation if it were sold separately. In accordance with ASC 340-40, any incremental costs incurred to obtain a contract with a customer are required to be capitalized and amortized over the period in which the goods and services are transferred to the customer. The incremental costs incurred in connection with the BGI Genomics arrangement is not material on an accumulated basis and therefore will not be capitalized on the balance sheet but will be expensed as incurred. ​ Foundation Medicine, Inc. In August 2019, the Company entered into a License and Collaboration Agreement (the “Foundation Medicine Agreement”) with Foundation Medicine to develop and commercialize personalized circulating tumor DNA monitoring assays, for use by biopharmaceutical and clinical customers who order Foundation Medicine’s FoundationOne CDx. The Foundation Medicine Agreement has an initial term of five years, expiring in August 2024, with automatic renewals thereafter for successive one-year terms, unless the Foundation Medicine Agreement is earlier terminated in accordance with its terms. Natera and Foundation Medicine will share the revenues generated from both biopharmaceutical and clinical customers in accordance with the terms of the Foundation Medicine Agreement. The Foundation Medicine Agreement provides for approximately $13.3 million in upfront licensing fees and prepaid revenues payable to the Company, and up to approximately $32.0 million in minimum annual payments and payments tied to the Company’s achievement of certain developmental, regulatory, and commercial milestones. As of December 31, 2019, the Company received $16.3 million of these amounts, of which $3.0 million was for achieving certain milestones, and $13.3 million was for licensing fees and prepaid revenue. There was an additional milestone met in May 2021. The Company recorded the $1.0 million milestone amount against accounts receivable and short-term deferred revenue. The milestone was paid ​ Pursuant to the agreement, the Company will provide development services in conjunction with granting the use of the Company’s intellectual property. Following completion of those development services, the Company will provide assay testing services over the term of the agreement. The Company has concluded that the license is not a distinct performance obligation as it is highly interrelated and interdependent with the related development services. Therefore, license and related development services represent a single performance obligation. ​ The Company is responsible for providing the technology license and certain development services that are required to customize its proprietary Signatera test to work with Foundation Medicine’s FoundationOne CDx. The intellectual property has been licensed to Foundation Medicine for the customized test. In addition, the Company is responsible for delivering clinical study plans in order to demonstrate efficacy of the customized test. Revenues associated with each of the performance obligations are recognized over time using the input method, based on costs incurred to perform the development services, since the level of costs incurred over time best reflect the transfer of development services. Revenue associated with the assay testing services will be recognized upon delivery of these services. Funds received in advance are recorded as deferred revenue and will be recognized as the related services are delivered. ​ The initial transaction price was primarily comprised of license and milestone fees. The Company constrains the estimated variable consideration when it assesses it is probable that a significant reversal in the amount of cumulative revenue recognized may occur in future periods. Certain milestone fees were constrained and not included in the transaction price due to the uncertainties of research and development. The Company re-evaluates the transaction price, including the estimated variable consideration included in the transaction price and all constrained amounts, in each reporting period and as uncertain events are resolved or other changes in circumstances occur. The allocation of the transaction price was performed based on standalone selling prices, which are based on estimated amounts that the Company would charge for a performance obligation if it were sold separately. ​ In accordance with ASC 340-40, any incremental costs incurred to obtain a contract with a customer are required to be capitalized and amortized over the period in which the goods and services are transferred to the customer. The Company has elected to apply a practical expedient under ASC 340-40 to recognize the incremental costs of obtaining a contract as an expense when incurred provided that the amortization period of such costs, if capitalized, is one year or less. Since the incremental costs to obtain the Foundation Medicine Agreement would be amortized over a period of one year or less, these costs were expensed as incurred. Disaggregation of Revenues ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2021 ​ 2020 ​ 2019 ​ ​ (in thousands) Insurance carriers ​ $ 492,563 ​ $ 300,220 ​ $ 210,919 Laboratory partners ​ ​ 100,019 ​ ​ 58,196 ​ ​ 59,876 Patients ​ ​ 32,904 ​ ​ 32,589 ​ ​ 31,533 Total revenues ​ $ 625,486 ​ $ 391,005 ​ $ 302,328 ​ The following table presents total revenues by geographic area based on the location of the Company’s payers: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2021 2020 2019 ​ ​ (in thousands) United States ​ $ 590,872 $ 365,660 $ 260,846 Americas, excluding U.S. ​ ​ 4,047 ​ 3,469 ​ 3,218 Europe, Middle East, India, Africa ​ ​ 20,429 ​ 14,332 ​ 15,434 Asia Pacific and Other ​ ​ 10,138 ​ 7,544 ​ 22,830 Total ​ $ 625,486 $ 391,005 ​ $ 302,328 ​ The following table summarizes the Company’s beginning and ending balances of accounts receivable and deferred revenues: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ Balance at ​ ​ December 31, ​ December 31, ​ ​ 2021 ​ 2020 ​ ​ (in thousands) Assets: ​ ​ ​ ​ ​ ​ Accounts receivable ​ $ 122,074 ​ $ 78,565 Liabilities: ​ ​ ​ ​ ​ ​ Deferred revenue, current portion ​ $ 7,404 ​ $ 50,125 Deferred revenue, long-term portion ​ ​ 21,318 ​ ​ 22,805 Total deferred revenues ​ $ 28,722 ​ $ 72,930 ​ ​ ​ ​ ​ ​ ​ ​ Deferred ​ ​ Revenues ​ ​ (in thousands) Balance at December 31, 2020 ​ $ 72,930 Increase in deferred revenues ​ ​ 7,915 Reclasses from deferred revenues to other to short-term liabilities ​ ​ (10,080) Revenue recognized during the period that was included in ​ ​ (37,784) Revenue recognized from performance obligations satisfied ​ ​ (4,259) Balance at December 31, 2021 ​ $ 28,722 ​ During the year ended December 31, 2021, revenue recognized that was included in the deferred revenue balance at the beginning of the period totaled $37.8 million with approximately $8.9 million related to BGI Genomics and Foundation Medicine, $28.6 million related to Qiagen and the remaining $0.3 million related to genetic testing services. During the year ended December 31, 2021, $4.3 million was recognized as deferred revenue and later earned as revenue in the same period. The current portion of deferred revenue includes $3.2 million from the BGI Genomics agreement and $0.5 million from the Foundation Medicine agreement. The non-current portion of deferred revenue includes $20.4 million from the BGI Genomics agreement and $0.9 million from the Foundation Medicine agreement.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Measurements
Fair Value Measurements	4. Fair Value Measurements ​ The Company's financial assets and liabilities carried at fair value are comprised of investment assets that include money market and investments. ​ The fair value accounting guidance requires that assets and liabilities be carried at fair value and classified in one of the following three categories: ​ Level I: Quoted prices in active markets for identical assets and liabilities that the Company has the ability to access. ​ Level II: Observable market-based inputs or unobservable inputs that are corroborated by market data, such as quoted prices, interest rates, and yield curves. ​ Level III: Inputs that are unobservable data points that are not corroborated by market data. ​ This hierarchy requires the Company to use observable market data, when available, and to minimize the use of unobservable inputs when determining fair value. ​ Assets and Liabilities That Are Measured at Fair Value on a Recurring Basis ​ The following table represents the fair value hierarchy for the Company’s financial assets and financial liabilities measured at fair value on a recurring basis: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ December 31, 2020 ​ Level I Level II Level III Total Level I Level II Level III Total ​ ​ (in thousands) Financial Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market deposits ​ $ 10,041 ​ $ — ​ $ — ​ $ 10,041 ​ $ 28,990 ​ $ — ​ $ — ​ $ 28,990 ​ U.S. Treasury securities ​ ​ 688,097 ​ ​ — ​ ​ — ​ ​ 688,097 ​ ​ 597,744 ​ ​ — ​ ​ — ​ ​ 597,744 ​ Corporate bonds and notes ​ ​ — ​ ​ 52,337 ​ ​ — ​ ​ 52,337 ​ ​ — ​ ​ 12,328 ​ ​ — ​ ​ 12,328 ​ Municipal securities ​ ​ — ​ ​ 89,462 ​ ​ — ​ ​ 89,462 ​ ​ — ​ ​ 78,534 ​ ​ — ​ ​ 78,534 ​ Total financial assets ​ $ 698,138 ​ $ 141,799 ​ $ — ​ $ 839,937 ​ $ 626,734 ​ $ 90,862 ​ $ — ​ $ 717,596 ​ ​ Fair Value of Long-Term Debt: As of December 31, 2021, the estimated fair value of the Convertible Notes, which are not presented at fair value on the Consolidated Balance Sheet as of December 31, 2021, was $715.7 million and was based upon observable Level 2 inputs, including pricing information from recent trades of the Convertible Notes (see Note 10, Debt

Financial Instruments

Financial Instruments	12 Months Ended
	Dec. 31, 2021
Financial Instruments
Financial Instruments	5. Financial Instruments ​ The Company elected to invest a portion of its cash assets in conservative, income earning, liquid investments. Cash equivalents and investments, all of which are classified as available-for-sale securities, consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ December 31, 2020 ​ Amortized Cost Gross Unrealized Gain Gross Unrealized (Loss) Estimated Fair Value Amortized Cost Gross Unrealized Gain Gross Unrealized (Loss) Estimated Fair Value ​ ​ (in thousands) Money market deposits ​ $ 10,041 ​ $ — ​ $ — ​ $ 10,041 ​ $ 28,990 ​ $ — ​ $ — ​ $ 28,990 ​ U.S. Treasury securities (1) ​ 689,640 ​ 1,081 ​ (2,624) ​ 688,097 ​ 594,252 ​ 3,512 ​ (20) ​ 597,744 ​ Corporate bonds and notes (1) ​ 52,729 ​ — ​ (392) ​ 52,337 ​ 12,331 ​ 2 ​ (5) ​ 12,328 ​ Municipal securities ​ ​ 89,814 ​ ​ 261 ​ ​ (613) ​ ​ 89,462 ​ ​ 77,764 ​ ​ 796 ​ ​ (26) ​ ​ 78,534 ​ Total ​ $ 842,224 ​ $ 1,342 ​ $ (3,629) ​ $ 839,937 ​ $ 713,337 ​ $ 4,310 ​ $ (51) ​ $ 717,596 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents (2) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 10,041 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 28,990 ​ Short-term investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 829,896 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 688,606 ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 839,937 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 717,596 ​ ​ (1) Per the Company’s investment policy, all debt securities are classified as short-term investments irrespective of holding period. (2) Cash equivalents includes cash sweep accounts and U.S. Treasury money market mutual funds. ​ The Company invests in U.S. Treasuries, U.S. agency and high quality municipal bonds which mature at par value and are all paying their coupons on schedule. The Company has therefore concluded there is currently no other than temporary impairment of its investments and will continue to recognize unrealized gains and losses in other comprehensive income (loss). The Company sold $187.6 million and $30.1 million of investments during the years ended December 31, 2021 and 2020, respectively. During the year ended December 31, 2021, the amount of gross realized gains and realized losses upon sales of investments were insignificant. The Company uses the specific investment identification method to calculate realized gains and losses and amounts reclassified out of other comprehensive income to net income. As of December 31, 2021, the Company had 61 investments in an unrealized loss position in its portfolio. An allowance for credit losses was not necessary as decrease in the fair market value for a majority of the available-for-sale securities was as a result of a significant average yield rate decrease for similar securities as of December 31, 2021. T he Company has assessed the unrealized loss position for available-for-sale debt securities for which an allowance for credit losses has not been recorded. The fair value for investment securities at an unrealized loss position as of December 31, 2021 was $604.7 million. The aggregate amount of unrealized losses of these securities was $ 3.6 million, and the impact of the securities in a continuous loss position to the consolidated statements of operations and comprehensive loss were not material as of December 31, 2021. ​ The following table summarizes the Company’s portfolio of available-for-sale securities by contractual maturity as of December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ Amortized Cost ​ Fair Value ​ ​ ​ (in thousands) ​ Less than or equal to one year ​ $ 274,879 ​ $ 275,331 ​ Greater than one year but less than five years ​ ​ 557,304 ​ ​ 554,565 ​ Total ​ $ 832,183 ​ $ 829,896 ​ ​

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2021
Balance Sheet Components
Balance Sheet Components	6. Balance Sheet Components ​ Credit Losses ​ The following is a roll-forward of the allowances for credit losses related to trade accounts receivable and other current assets for the years ended December 31, 2021, 2020 and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ December 31, ​ 2021 ​ 2020 ​ 2019 ​ (in thousands) Beginning balance $ 4,220 ​ $ 2,919 ​ $ 1,788 Cumulative-effect adjustment upon adoption of ASU 2016-13 ​ — ​ ​ 404 ​ ​ — Provision for credit losses ​ (156) ​ ​ 1,354 ​ ​ 1,141 Write offs ​ (1,635) ​ ​ (457) ​ ​ (10) Ending balance $ 2,429 ​ $ 4,220 ​ $ 2,919 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Property and Equipment, net ​ The Company’s property and equipment consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ Useful Life 2021 2020 ​ ​ ​ ​ ​ (in thousands) ​ Machinery and equipment 3-5 years $ 33,722 ​ $ 51,001 ​ Furniture and fixtures 3 years ​ — ​ 1,376 ​ Computer equipment 3 years ​ 4,893 ​ 2,428 ​ Capitalized software held for internal use ​ 3 years ​ ​ 2,395 ​ ​ 7,417 ​ Leasehold improvements Life of lease ​ 13,640 ​ 14,810 ​ Construction-in-process ​ ​ ​ 30,279 ​ 6,370 ​ ​ ​ ​ ​ 84,929 ​ 83,402 ​ Less: Accumulated depreciation and amortization ​ ​ ​ (19,413) ​ (50,054) ​ Total Property and Equipment, net ​ ​ ​ $ 65,516 ​ $ 33,348 ​ ​ The Company’s property and equipment are primarily located in the United States. ​ During the year ended December 31, 2021, the increase in net property and equipment was due to purchases of new equipment for the Company’s laboratories located in Texas and California to expand testing capabilities, offset by depreciation expense of $11.3 million recorded in the year ended December 31, 2021. During the year ended December 31, 2021, the Company has written off $41.9 million in fully depreciated assets. The Company did not incur an impairment charge during the year ended December 31, 2021. ​ ​ Accrued Compensation ​ The Company’s accrued compensation consisted of the following: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2021 2020 ​ ​ (in thousands) ​ Accrued paid time off ​ $ 2,567 ​ $ 2,260 ​ Accrued commissions ​ 15,726 ​ 12,686 ​ Accrued bonuses ​ 15,854 ​ 9,635 ​ Other accrued compensation ​ 6,794 ​ 5,790 ​ Total accrued compensation ​ $ 40,941 ​ $ 30,371 ​ ​ Other Accrued Liabilities ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ 2021 2020 ​ ​ (in thousands) Reserves for refunds to insurance carriers ​ $ 17,210 ​ $ 17,366 ​ Accrued charges for third-party testing ​ ​ 5,849 ​ ​ 5,141 ​ Testing and laboratory materials from suppliers ​ ​ 3,799 ​ ​ 2,720 ​ Marketing and corporate affairs ​ ​ 7,853 ​ ​ 3,325 ​ Legal, audit and consulting fees ​ ​ 11,758 ​ ​ 4,189 ​ Accrued shipping charges ​ ​ 969 ​ ​ 1,604 ​ Sales tax payable ​ ​ 2,230 ​ ​ 1,723 ​ Accrued third-party service fees ​ ​ 13,442 ​ ​ 2,355 ​ Clinical trials, studies, and other development ​ 11,218 ​ 2,353 ​ Operating lease liabilities, current portion ​ ​ 5,752 ​ ​ 7,300 ​ Fixed asset purchases ​ ​ 1,853 ​ ​ 1,691 ​ Other accrued interest ​ ​ 1,078 ​ ​ 1,078 ​ Other accrued expenses ​ 10,342 ​ 9,562 ​ Total other accrued liabilities ​ $ 93,353 ​ $ 60,407 ​ ​ Reserves for refunds to insurance carriers include overpayments from and amounts to be refunded to insurance carriers, and additional amounts that the Company estimates for potential refund requests during the period. When the Company releases these previously accrued amounts, they are recognized as product revenues in the statements of operations and comprehensive loss. ​ The following table summarizes the reserve balance and activities for refunds to insurance carriers for the year ended December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ 2021 2020 ​ ​ (in thousands) Beginning balance ​ $ 17,366 ​ $ 9,410 Additional reserves ​ ​ 16,340 ​ ​ 19,427 Refunds to carriers ​ ​ (10,784) ​ ​ (6,066) Reserves released to revenue ​ ​ (5,712) ​ ​ (5,405) Ending balance ​ $ 17,210 ​ $ 17,366 ​ ​ ​ ​ ​ ​ ​ ​

Leases

Leases	12 Months Ended
	Dec. 31, 2021
Leases.
Leases	7. Leases ​ Operating Leases ​ 36-month 24-month one ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ (in thousands) Operating lease liabilities, current portion included in other accrued liabilities ​ $ 5,752 Operating lease liabilities, long-term portion ​ ​ 61,036 Total operating lease liabilities ​ $ 66,788 ​ rate to each lease was not readily determinable. In accordance with ASC 842, the incremental borrowing rate was estimated as the annual percentage yield resulting from a corporate debt financing over a loan term approximating the remaining term of each lease, with the effect of certain credit risk rating. As of December 31, 2021, the weighted-average remaining lease term was 4.77 The Company continues to recognize lease expense on a straight-line basis. The lease expense includes the amortization of the right-of-assets with the associated interest component estimated by applying the effective interest method. Total lease expense recognized in the statements of operations and comprehensive loss were $10.9 million, $7.8 million, and $7.8 million for the years ended December 31, 2021, 2020, and 2019, respectively. Cash paid for amounts in the measurement of operating lease liabilities totaled $10.3 million, $9.0 million, and $8.6 million for the years ended December 31, 2021, 2020, and 2019, respectively. The present value of the future minimum lease payments under all non-cancellable operating leases as of December 31, 2021 is as follows: ​ ​ ​ ​ ​ ​ ​ Operating Leases ​ ​ (in thousands) Year ending December 31: ​ ​ ​ ​ 2022 ​ $ 9,980 ​ 2023 ​ ​ 11,082 ​ 2024 ​ ​ 12,258 ​ 2025 ​ ​ 12,494 ​ 2026 ​ ​ 12,845 ​ 2027 and thereafter ​ ​ 27,331 ​ Total future minimum lease payments ​ ​ 85,990 ​ Less: imputed interest ​ ​ (19,202) ​ Operating lease liabilities ​ $ 66,788 ​ ​

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies
Commitments and Contingencies	8. Commitments and Contingencies ​ Legal Proceedings From time to time, the Company is involved in disputes, litigation, and other regulatory or administrative actions, including those with respect to intellectual property, employment, testing, billing, reimbursement and other matters. Such actions may include allegations of negligence, products/professional liability or other legal claims, and could involve claims for substantial compensatory and/or punitive damages or claims for indeterminate amounts of damages. The Company is aggressively defending and/or prosecuting its current litigation matters, but cannot provide any assurance as to the ultimate outcome or that an adverse resolution would not have a material adverse effect on its financial condition and results of operations. There are many uncertainties associated with any litigation and these actions or other third party claims against the Company, including by governmental entities, or by the Company against third parties, may cause the Company to incur costly litigation and/or substantial settlement charges. In addition, the resolution of any intellectual property litigation may require the Company to make royalty payments, which could adversely affect gross margins in future periods. If this were to occur, the Company's business, financial condition, results of operations, and cash flows could be adversely affected. The Company assesses legal contingencies to determine the degree of probability and range of possible loss for potential accrual in its financial statements. When evaluating legal contingencies, the Company may be unable to provide a meaningful estimate due to a number of factors, including the procedural status of the matter in question, the presence of complex or novel legal theories, and/or the ongoing discovery and development of information important to the matters. In addition, damage amounts claimed in litigation or other matters may be unsupported, exaggerated or unrelated to possible outcomes, and as such are not meaningful indicators of its potential liability. During the periods presented, the Company has not recorded any accrual for loss contingencies associated with such legal proceedings or other matters, determined that an unfavorable outcome is probable or reasonably possible, or determined that the amount or range of any possible loss is reasonably estimable. Intellectual Property Litigation Matters. The Company has been involved in two patent litigations against CareDx, Inc. (“CareDx”) in the United States District Court for the District of Delaware (“CareDx Patent Cases”). In the first suit, CareDx alleged, in a complaint filed jointly with the Board of Trustees of the Leland Stanford Junior University (“Stanford”) in March 2019 and amended in March 2020, that the Company infringed three patents. The complaint sought unspecified damages and injunctive relief. On September 28, 2021, the Court granted the Company’s motion for summary judgment, finding all three of Stanford’s patents invalid. CareDx and Stanford have filed a notice of appeal to the United States Court of Appeals for the Federal Circuit. In the second suit, filed by the Company in January 2020, the Company alleged infringement by CareDx of two of the Company’s patents, seeking unspecified damages and injunctive relief. The case is currently pending and is scheduled for trial in July 2023. The Company has filed suit against ArcherDX, Inc. (“ArcherDX”) in the United States District Court for the District of Delaware, alleging, in complaints filed in January, April, and August of 2020, which cases were consolidated in September 2020, that certain ArcherDX DNA oncology products infringe five of the Company’s patents. In June 2020, ArcherDX filed a motion to dismiss aspects of the Company’s case, including to invalidate several of the Company’s asserted patents. That motion was denied in its entirety in October 2020. In January 2021, the Company filed a second amended complaint naming an additional Archer DX entity, ArcherDx LLC, and Invitae Corp. as defendants. The Company is seeking unspecified monetary damages and injunctive relief. Both parties filed motions for summary judgment in January 2022. A jury trial is currently set for May 16, 2022. The Company is the subject of a lawsuit filed against it by Ravgen, Inc. (“Ravgen”) in June 2020 in the United States District Court for the Western District of Texas, alleging infringement of two Ravgen patents. The complaint seeks monetary damages and injunctive relief. Various parties, including Natera, have filed challenges to the validity of the asserted patents with the Patent Office, which are pending. The Company filed suit against Progenity, Inc. (“Progenity”) in June 2020 in the United States District Court for the Western District of Texas and in the United States District Court for the Northern District of Texas, in each case alleging that Progenity’s NIPT test infringes six of the Company’s patents. The complaints sought treble damages and injunctive relief. In July 2020, Progenity filed suit against the Company in the United States District Court for the Southern District of California, seeking declaratory judgment of non-infringement of the Company’s asserted patents. Progenity also petitioned the Patent Trial and Appeal Board (“PTAB”) of the United States Patent and Trademark Office for inter partes In October 2020, the Company filed suit against Genosity Inc. (“Genosity”), in the United States District Court for the District of Delaware, alleging that various Genosity oncology products infringe one of the Company’s patents and seeking unspecified monetary damages and injunctive relief. In March 2021, the Company filed a motion to dismiss certain of Genosity’s affirmative defenses and a counterclaim. Trial is set for October 2023. ​ In January 2021, the Company filed suit against Inivata, Inc. and Inivata Ltd. (collectively “Inivata”) in the United States District Court for the District of Delaware. The complaint, amended by the Company in May 2021, alleges that various Inivata oncology products infringe two of the Company’s patents and seeks unspecified monetary damages and injunctive relief. In June 2021, Inivata filed a motion to dismiss the Company’s amended complaint. ​ The Company is the subject of lawsuits filed against it by Invitae Corp. (“Invitae”) in the United States District Court of the District of Delaware alleging, in complaints filed in May and November of 2021, infringement of three patents and seeking monetary damages and injunctive relief. Trial is set for January 2024. Other Litigation Matters. In August 2019, a suit was filed against the Company in the Circuit Court of Cook County, Illinois by a patient alleging claims relating to a discordant test result and seeking monetary damages. The suit was dismissed in June 2021. The Company is also the subject of a lawsuit filed by CareDx against the Company in April 2019 in the United States District Court for the District of Delaware, alleging false advertising, trademark disparagement, unfair competition, and unfair or deceptive trade practices based on statements describing studies that concern the Company’s technology and CareDx’s technology (“CareDx’s Advertising Case”). The complaint seeks unspecified damages and injunctive relief. In May 2019, the Company filed a motion to dismiss the entirety of CareDx’s Advertising Case for failure to state a claim, following which in February 2020, CareDx filed an amended complaint withdrawing its trademark disparagement claim. Also in February 2020, the Company filed a counterclaim against CareDx in the United States District Court for the District of Delaware, alleging false advertising, unfair competition and deceptive trade practices and seeking unspecified damages and injunctive relief. The parties cross-moved for partial summary judgment, which was denied in April 2021. The matter is set for trial on March 7, 2022. The Company is involved in litigation against Guardant, Inc. (“Guardant”). On or about May 27, 2021, Guardant filed suit against the Company in the United States District Court of the Northern District of California alleging false advertising and related claims and seeking unspecified damages and injunctive relief. On or about May 28, 2021, the Company filed suit against Guardant in the Western District of Texas, alleging false advertising and related claims. The Company has voluntarily dismissed its Texas suit against Guardant. In the California action, the Company has answered Guardant’s complaint and has asserted its claims as counterclaims, seeking unspecified damages and injunctive relief. On August 3, 2021, Guardant moved to dismiss the Company’s counterclaims, which motion was denied in all material respects. In November 2021, a purported class action lawsuit was filed against the Company in the United States District Court for the Northern District of California, by a patient alleging various causes of action relating to the Company’s patient billing and seeks, among other relief, class certification, injunctive relief, restitution and/or disgorgement, attorneys’ fees, and costs. In February 2022, a purported class action lawsuit was filed against the Company in the United States District Court for the Northern District of California, by a patient alleging various causes of action related to the marketing of Panorama and seeks, among other relief, class certification, monetary damages, attorneys’ fees, and costs. Director and Officer Indemnifications As permitted under Delaware law, and as set forth in the Company’s Amended and Restated Certificate of Incorporation and its Amended and Restated Bylaws, the Company indemnifies its directors, executive officers, other officers, employees and other agents for certain events or occurrences that may arise while in such capacity. The maximum potential amount of future payments the Company could be required to make under this indemnification is unlimited; however, the Company has insurance policies that may limit its exposure and may enable it to recover a portion of any future amounts paid. Assuming the applicability of coverage, the willingness of the insurer to assume coverage, and subject to certain retention, loss limits and other policy provisions, the Company believes any obligations under this indemnification would not be material, other than standard retention amounts for securities related claims. However, no assurances can be given that the covering insurers will not attempt to dispute the validity, applicability, or amount of coverage without expensive litigation against these insurers, in which case the Company may incur substantial liabilities as a result of these indemnification obligations. Third-Party Payer Reimbursement Audits From time to time, the Company receives recoupment requests from third-party payers for alleged overpayments. The Company disagrees with the contentions of pending requests and/or has recorded an estimated reserve for the alleged overpayments. ​ Contractual Commitments ​ The following table sets forth the material unconditional purchase obligations and contractual commitments as of December 31, 2021 with a remaining term of at least one year: ​ ​ ​ ​ ​ Party Total Commitments Expiry Date ​ ​ (in thousands) ​ Material suppliers $ 16,040 June 2026 Application service providers ​ 35,279 March 2026 Earnouts for development with third party (1) ​ 35,000 September 2023 Software development provider ​ 4,463 December 2024 Leases (2) ​ 29,683 March 2033 Other material suppliers ​ 17,510 Various Total ​ 137,975 ​ ​ ​ ​ ​ (1) The earnouts for asset development with the acquired Canadian entity consists of three milestones which are achieved upon the satisfaction of certain contractual conditions. Upon achievement, the earnout consideration will primarily be paid in the Company’s common stock. ​ (2) Represents executed leases which have not commenced. Please refer to Note 7, Leases , for additional information .

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2021
Stock-Based Compensation
Stock-Based Compensation	9. Stock-Based Compensation ​ Equity Plans ​ 2015 Equity Incentive Plan ​ General ​ Share Reserve The initial number of shares of the Company’s common stock available for issuance under the 2015 Plan was 3,451,495 shares. The number of shares reserved for issuance under the 2015 Plan will be increased automatically on the first business day of each fiscal year, commencing in 2016, by a number equal to the smallest of ​ ● 3,500,000 shares; ​ ● 4% of the shares of common stock outstanding on the last business day of the prior fiscal year; or ​ ● the number of shares determined by the Company’s board of directors. ​ Stock options vest as determined by the compensation committee. In general, they will vest over a four-year period following the date of grant. Stock options expire at the time determined by the compensation committee but in no event more than ten years ​ Restricted Shares and Stock Units. ​ 2015 Employee Stock Purchase Plan ​ General ​ Share Reserve. ​ ● 880,000 shares; ​ ● 1% of the shares of common stock outstanding on the last business day of the prior fiscal year; or ​ ● the number of shares determined by the Company’s board of directors. ​ The number of shares reserved under the 2015 ESPP will automatically be adjusted in the event of a stock split, stock dividend or a reverse stock split (including an adjustment to the per-purchase period share limit). ​ Purchase Price. shares may be purchased during any offering period. A participant shall not be granted an option under the ESPP if such option would permit the participant’s rights to purchase stock to accrue at a rate exceeding $25,000 fair market value of stock for each calendar year in which such option is outstanding at any time. ​ Offering Periods. ​ The following table summarizes the offering activity during the years ended December 31, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Total ​ ​ Shares Purchased ​ Proceeds Offering Period ​ (in thousands) November 1, 2019 - April 30, 2020 ​ 97,247 ​ $ 3,062 May 1, 2020 - October 31, 2020 ​ 136,288 ​ $ 4,052 November 1, 2020 - April 30, 2021 ​ 106,435 ​ $ 6,085 May 1, 2021 - October 31, 2021 ​ 79,820 ​ $ 7,465 ​ Stock Options ​ The following table summarizes option and RSU activity during the year ended December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding Options ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ Shares ​ ​ ​ Average ​ Remaining ​ Aggregate ​ ​ Available for ​ Number of ​ Exercise ​ Contractual ​ Intrinsic ​ ​ Grant ​ Shares ​ Price ​ Life ​ Value (in thousands, except for contractual life and exercise price) ​ ​ ​ ​ ​ ​ ​ ​ (in years) ​ ​ Balance at December 31, 2020 3,148 6,707 ​ $ 11.19 6.04 ​ $ 592,468 ​ Additional shares authorized 3,446 ​ — ​ $ — ​ ​ ​ ​ ​ ​ Options granted (391) 391 ​ $ 104.03 ​ ​ ​ ​ ​ ​ Options exercised — (1,165) ​ $ 10.14 ​ ​ ​ ​ ​ ​ Options forfeited/cancelled 33 (33) ​ $ 15.00 ​ ​ ​ ​ ​ ​ RSUs granted ​ (2,208) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ RSUs forfeited/cancelled ​ 291 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at December 31, 2021 4,319 5,900 ​ $ 17.54 5.40 ​ $ 451,505 ​ Exercisable at December 31, 2021 ​ ​ 4,977 ​ $ 10.65 4.90 ​ $ 411,841 ​ Vested and expected to vest at December 31, 2021 ​ ​ 5,840 ​ $ 17.17 5.37 ​ $ 449,026 ​ ​ The total intrinsic value of stock options exercised during the years ended December 31, 2021, 2020, and 2019 were $97.0 million, $184.7 million, and $70.0 million, respectively. ​ The weighted-average grant date fair value of options granted during the years ended December 31, 2021, 2020, and 2019 were $104.03, $27.70 and $8.01 per share, respectively. ​ ​ Performance-based Awards The Company grants certain senior-level executives performance stock options and units which vest based on either market and time-based service conditions or performance and time-based service conditions, which are referred to herein as performance-based awards. The Company has assessed the performance-based award with the appropriate valuation method and has recognized the applicable stock-based compensation expense. The following table summarizes the performance-based and market-based awards as of December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Period Granted ​ Options Granted ​ RSUs Granted ​ Options Vested ​ RSUs Vested ​ Milestone ​ Valuation Method (in thousands) Q1 2019 ​ 200 ​ 300 ​ 200 ​ 300 ​ (1) ​ Monte-Carlo Simulation Q2 2019 ​ — ​ 188 ​ — ​ 81 ​ (2) ​ Fair Market Value Q3 2019 ​ — ​ 50 ​ — ​ 50 ​ (1) ​ Monte-Carlo Simulation Q1 2020 ​ 150 ​ 300 ​ 130 ​ 289 ​ (1) ​ Monte-Carlo Simulation Q1 2020 ​ — ​ 436 ​ — ​ 408 ​ (3) ​ Fair Market Value Q1 2020 ​ 129 ​ — ​ 129 ​ — ​ (3) ​ Black-Scholes-Merton Q2 2020 ​ — ​ 21 ​ — ​ 21 ​ (3) ​ Fair Market Value Q3 2020 ​ 10 ​ — ​ 10 ​ — ​ (4) ​ Black-Scholes-Merton Q3 2020 ​ — ​ 27 ​ — ​ 17 ​ (3) ​ Fair Market Value Q4 2020 ​ — ​ 32 ​ — ​ 19 ​ (1) ​ Monte-Carlo Simulation Q4 2020 ​ — ​ 22 ​ — ​ 2 ​ (5) ​ Fair Market Value Q1 2021 ​ 150 ​ 125 ​ — ​ — ​ (1) ​ Monte-Carlo Simulation Q1 2021 ​ — ​ 279 ​ — ​ 10 ​ (3) ​ Fair Market Value Q2 2021 ​ 163 ​ — ​ — ​ — ​ (1) ​ Monte-Carlo Simulation Q2 2021 ​ 29 ​ — ​ — ​ — ​ (3) ​ Black-Scholes-Merton Q2 2021 ​ — ​ 7 ​ — ​ — ​ (3) ​ Fair Market Value Q4 2021 ​ — ​ 20 ​ — ​ — ​ (1) ​ Monte-Carlo Simulation Q4 2021 ​ — ​ 205 ​ — ​ — ​ (3) ​ Fair Market Value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) The awards vest based on the achievement of certain values of the Company’s common stock at multiple thresholds within certain periods and are contingent upon the completion of requisite service through the date of such vesting. (2) The vesting of the awards will be triggered after the end of the achievement milestone, as measured by the Company. (3) The awards vest based on achievement of certain revenue targets, units, and system implementation, contingent upon the completion of requisite service through the date of such vesting. (4) The awards have vested based on a change of coverage. (5) The awards will vest based on achievement of certain revenue and recruiting targets. ​ The Company has recognized $50.3 million in stock-based compensation for performance-based awards for the year ended December 31, 2021 compared to $17.2 million in stock-based compensation for performance-based awards for the year ended December 31, 2020. ​ The fair value of the performance-based awards with market conditions granted estimated using a Monte Carlo simulation model used the following inputs for the years ended December 31, 2021 and 2020: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ 2021 2020 Risk-free interest rate ​ 0.80 % — 1.52 % ​ 0.54 % — 1.64 % Expected dividend yield ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ Expected volatility ​ ​ ​ ​ 60 % ​ 55 ​ ​ 65 % Expected term (years) ​ 7.25 ​ — 10.0 ​ ​ 5.25 ​ — 7.25 ​ ​ Restricted Stock Units ​ The following table summarizes restricted stock unit (“RSU”) activity for the year ended December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Grant Date ​ ​ Shares ​ Fair Value ​ ​ (in thousands) ​ ​ ​ Balance at December 31, 2020 ​ 4,188 ​ $ 34.02 Granted ​ 2,208 ​ $ 106.74 Vested ​ (2,117) ​ $ 29.46 Canceled/Forfeited ​ (291) ​ $ 55.16 Balance at December 31, 2021 3,988 ​ $ 74.33 ​ ​ ​ ​ ​ ​ ​ Stock-Based Compensation Expense ​ Stock based compensation is related to stock options and RSUs granted to the Company’s employees and is measured at the grant date based on the fair value of the award. The fair value is recognized as expense over the requisite service period, which is generally the vesting period of the respective awards on a straight-line basis. No compensation cost is recognized when the requisite service has not been met and the awards are therefore forfeited. Employee stock-based compensation expense was calculated based on awards ultimately expected to vest and has been reduced for estimated forfeitures. Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods, if actual forfeitures differ from those estimates. Non-employee stock-based compensation expense was not adjusted for estimated forfeitures up until the occurrence of the actual forfeiture of the associated awards. ​ The following table presents the effect of employee and non-employee stock-based compensation expense on selected statements of operations line items for the years ended December 31, 2021, 2020, and 2019. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2021 ​ 2020 ​ 2019 ​ Employee Non-Employee Total Employee Non-Employee Total Employee Non-Employee Total ​ (in thousands) ​ Cost of revenues ​ $ 4,811 ​ $ — ​ $ 4,811 ​ $ 1,691 ​ $ — ​ $ 1,691 ​ $ 905 ​ $ 32 ​ $ 937 ​ Research and development ​ 24,507 ​ 1,361 ​ 25,868 ​ 10,777 ​ 647 ​ 11,424 ​ ​ 5,354 ​ — ​ 5,354 ​ Selling, general and administrative ​ 84,368 ​ 172 ​ 84,540 ​ 36,747 ​ 309 ​ 37,056 ​ ​ 21,730 ​ 603 ​ 22,333 ​ Total ​ $ 113,686 ​ $ 1,533 ​ $ 115,219 ​ $ 49,215 ​ $ 956 ​ $ 50,171 ​ $ 27,989 ​ $ 635 ​ $ 28,624 ​ ​ As of December 31, 2021, approximately $233.3 million of unrecognized compensation expense, adjusted for estimated forfeitures, related to unvested option awards and RSUs will be recognized over a weighted-average period of approximately 2.8 years. ​ Valuation of Stock Option Grants to Employees and Non-Employees ​ The Company utilizes Black-Scholes option pricing model when estimating the fair value of stock options. For the year ended December 31, 2021 the following valuation assumptions were applied on both the employee and non- employee options. In the same period of the prior year, the valuation assumptions as follows were only used for stock options granted to employees. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2021 2020 2019 ​ Expected term (years) 5.11 ​ — 10.00 ​ ​ 5.22 ​ — 10.00 ​ ​ 5.23 ​ — 10.00 ​ Expected volatility 55.33 % — 63.30 % 49.94 % — 61.96 % ​ 42.53 % — 45.84 % Expected dividend rate ​ ​ ​ 0 % ​ ​ ​ 0 % ​ ​ ​ ​ 0 % Risk-free interest rate 0.81 % — 1.67 % 0.31 % — 1.70 % ​ 1.60 % — 2.60 % ​ As of December 31, 2021, total options outstanding include 31,553 shares of option awards that were granted to non-employees, of which 730 shares are unvested. Stock-based compensation expense related to stock options granted to non-employees is recognized as the stock option is earned and the services are rendered. The Company believes that the estimated fair value of the stock options is more readily measurable than the fair value of the services rendered.

Debt

Debt	12 Months Ended
	Dec. 31, 2021
Debt
Debt	10. Debt ​ Credit Line Agreement ​ In September 2015, the Company entered into a credit line with UBS (the “Credit Line”) providing for a $50.0 million revolving line of credit which can be drawn down in increments at any time. The Credit Line was amended in July 2017 and bears interest at 30-day LIBOR plus 1.10%, and it is secured by a first priority lien and security interest in the Company’s money market and marketable securities held in its managed investment account with UBS. UBS has the right to demand full or partial payment of the Credit Line Obligations and terminate the Credit Line, in its discretion and without cause, at any time. ​ For the years ended December 31, 2021, 2020, and 2019, the Company recorded interest expense of $0.6 million, $0.8 million, and $1.7 million, respectively. Interest payments totaling $0.6 million, $0.8 million, and $1.7 million had been made on the Credit Line during the years ended December 31, 2021, 2020, and 2019, respectively. As of December 31, 2021, remaining accrued interest was $1.1 million, and the total principal amount outstanding including accrued interest was $49.0 million. ​ Convertible Notes ​ ​ ​ ​ ● During any fiscal quarter commencing after September 30, 2020 (and only during such fiscal quarter), if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding fiscal quarter is greater than or equal to 130% of the conversion price on each applicable trading day. ● During the five business day period after any five consecutive trading day period in which the trading price per $1,000 principal amount of Convertible Notes for each trading day of that five -day consecutive trading period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day. ● If the Company calls any or all of the Convertible Notes for redemption at any time prior to the close of business on the second business day prior to the redemption date. ● Upon the occurrence of certain distributions. ● Upon the occurrence of specified corporate transactions. ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ (in thousands) ​ Liability Component ​ ​ ​ Outstanding Principal $ 287,500 ​ Unamortized debt discount and debt issuance cost ​ (7,106) ​ Net carrying amount $ 280,394 ​ ​ ​ The following table presents total interest expense recognized related to the Convertible Notes during the year ended December 31, 2021: ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2021 ​ (in thousands) Cash interest expense ​ ​ ​ Contractual interest expense $ 6,469 ​ Non-cash interest expense ​ ​ ​ Amortization of debt discount and debt issuance cost ​ 1,227 ​ Total interest expense $ 7,696 ​ ​

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity
Stockholders' Equity	11. Stockholders’ Equity ​ In April 2019, the Company completed an underwritten equity offering to sell 5,263,158 shares of its common stock at a price to the public of $19 per share. On April 26, 2019, the Company sold an additional 789,473 shares of its common stock to the underwriters at the same price upon their exercise of the option to purchase those shares. Before offering expenses of $0.6 million, the Company received proceeds of $108.1 million net of the underwriting discount. In October 2019, the Company completed an underwritten equity offering to sell 5,714,286 shares of its common stock at a price to the public of $35 per share. The same day, the Company sold an additional 857,142 shares of its common stock to the underwriters at the same price upon their exercise of the option to purchase those shares. Before offering expenses of $0.4 million, the Company received proceeds of $216.2 million net of the underwriting discount. In September 2020, the Company completed an underwritten equity offering and sold 4,791,665 shares of its common stock at a price of $60 per share to the public. Before offering expenses of $0.3 million, the Company received proceeds of $271.0 million net of the underwriting discount. In July 2021, the Company completed an underwritten equity offering and sold 5,175,000 shares of its common stock at a price of $113 per share to the public. Before offering expenses of $0.4 million, the Company received proceeds of $551.2 million net of the underwriting discount. On September 10, 2021, the Company entered into an agreement with a third party for an asset acquisition where the acquired asset was in-process research and development primarily in exchange for an equity consideration payment. The total upfront acquisition consideration amounts to $35.6 million composed of the issuance of 276,346 shares of the Company's common stock with a fair value of $30.9 million, approximately $3.9 million of cash consideration, assumed net liabilities of $0.2 million, as well as $0.6 million of acquisition related legal and accounting costs directly attributable to the acquisition of the asset. As of December 31, 2021, the Company had 50,000,000 authorized shares of its preferred stock, of which no shares were issued and outstanding outstanding

Disposal of Business

Disposal of Business	12 Months Ended
	Dec. 31, 2021
Disposal of Business
Disposal of Business	​ 12. Disposal of Business ​ Sale of Evercord ​ In September 2019, the Company sold the Evercord business that provides cord blood and cord tissue processing and storage services for total estimated consideration of $15.4 million, including $9.7 million in cash, $1.0 million of cash deposited in a third-party escrow account recorded in short-term other receivables, and $4.7 million of additional consideration. The additional consideration is primarily related to the accounts receivable transferred to the buyer. The cash held in escrow serve as security for the indemnification obligations of the Company and eligible for release 12 months after the closing date. The assets relating to the Evercord services transferred to the buyer had a net book value of $6.2 million as of the sale date, and consisted of accounts receivables and equipment. The obligations and liabilities relating to the Evercord services transferred to the buyer consisted of deferred revenues of $5.2 million. The sale of the Evercord business did not meet criteria to be reported as a discontinued operation, because it did not represent a strategic shift with a major effect on the Company’s operations and financial results. The Company recognized a gain of $14.4 million on the sale, which was included in Loss from operations in the Consolidated Statements of Operations and Comprehensive Loss. The following table summarizes the computation of the gain realized from the disposal of business: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2019 ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ Proceeds on disposal: ​ ​ ​ ​ $ 15,377 Assets sold: ​ ​ ​ ​ ​ ​ Accounts receivable, net ​ ​ ​ ​ ​ 5,782 Equipment and inventory ​ ​ ​ ​ ​ 419 Total assets sold ​ ​ ​ ​ $ 6,201 Liabilities assumed by purchaser: ​ ​ ​ ​ ​ ​ Deferred revenues ​ ​ ​ ​ ​ 5,212 Net assets and liabilities sold ​ ​ ​ ​ $ 989 Net gain realized on disposal ​ ​ ​ ​ $ 14,388 ​ In connection with the sale of the Evercord business, the Company recorded impairment expense on the retained assets previously used in this business of $1.7 million in selling, general, and administrative expenses in the consolidated statement of operations and comprehensive loss. This expense is comprised of $1.2 million from the impairment of leasehold improvements, $0.1 million from the impairment of capitalized software held for internal use, and $0.4 million of right-of-use asset from the storage facility lease. In addition, the Company expects to incur $0.4 million of exit or disposal activity—$0.1 million of involuntary employee termination benefits were incurred in the third quarter of 2019, recorded in selling, general and administrative expense in the consolidated statements of operations and comprehensive loss, and $0.3 million of early contract termination fee from biological sample processing and storage provider to be incurred in the next fiscal year.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Taxes
Income Taxes	13. Income Taxes ​ The Company's effective tax rates for the years ended December 31, 2021, 2020, and 2019 differ from the U.S. federal statutory rate as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ 2019 ​ ​ ​ (in thousands, except percentages) ​ U.S. federal taxes (benefit) at statutory rate ​ $ (98,931) ​ (21.00) % ​ $ (48,226) ​ (21.00) % ​ $ (25,794) (21.00) % State tax expense ​ ​ (29,206) ​ (6.20) % ​ ​ (10,672) ​ (4.65) % ​ ​ (6,607) ​ (5.38) % Research and development credits ​ ​ (9,193) ​ (1.95) % ​ ​ (3,964) ​ (1.73) % ​ ​ (1,645) ​ (1.34) % Stock-based compensation ​ ​ (46,128) ​ (9.80) % ​ ​ (23,791) ​ (10.36) % ​ ​ (7,544) ​ (6.14) % Foreign tax ​ ​ 167 ​ 0.04 % ​ ​ 55 ​ 0.02 % ​ ​ 1,612 ​ 1.31 % Other nondeductible items ​ ​ 344 ​ 0.07 % ​ ​ 792 ​ 0.35 % ​ ​ 769 ​ 0.63 % Nondeductible officers' compensation ​ ​ 24,387 ​ 5.18 % ​ ​ 8,984 ​ 3.91 % ​ ​ 609 ​ 0.50 % Acquisition costs ​ ​ 8,901 ​ 1.89 % ​ ​ — ​ — % ​ ​ — ​ — % Change in valuation allowance ​ ​ 150,277 ​ 31.90 % ​ ​ 76,920 ​ 33.50 % ​ ​ 40,599 ​ 33.05 % Provision for income taxes ​ $ 618 ​ 0.13 % ​ $ 98 ​ 0.04 % ​ $ 1,999 ​ 1.63 % ​ During the year ended December 31, 2021, the Company recorded total income tax expense of $0.6 million. The Company provides testing to clinics and also licenses its cloud-based software to licensees that are based in a foreign country, which contributed to a foreign income tax expense of $0.3 million. Total income tax expense also included a state income tax expense of $0.3 million for the year ended December 31, 2021. ​ During the year ended December 31, 2020, the Company recorded total income tax expense of $0.1 million. The Company provides testing to clinics and also licenses its cloud-based software to licensees that are based in a foreign country, which contributed to a foreign income tax expense of $0.1 million. Total income tax expense also included a state income tax benefit of $9,000 for the year ended December 31, 2020. During the year ended December 31, 2019, the Company recorded total income tax expense of $2.0 million, which included a foreign withholding tax expense of $1.9 million, foreign income tax expense of $0.1 million and state income tax benefit of $0.04 million. ​ ​ Deferred income taxes reflect the net tax effects of temporary differences between carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes as well as net operating loss and tax credit carryforwards. The components of the net deferred income tax assets are as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ 2021 ​ 2020 ​ ​ ​ ​ ​ ​ (in thousands) ​ Deferred tax assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ ​ ​ ​ $ 315,552 ​ $ 177,899 ​ Intangibles ​ ​ ​ ​ ​ 4,443 ​ ​ — ​ Research and development tax credit carryforwards ​ ​ ​ ​ ​ 38,725 ​ ​ 24,332 ​ Reserves and accruals ​ ​ ​ ​ ​ 14,098 ​ ​ 21,770 ​ Lease Liabilities ​ ​ ​ ​ ​ 16,843 ​ ​ 7,123 ​ Deferred revenue ​ ​ ​ ​ ​ 6,363 ​ ​ 6,386 ​ Stock-based compensation ​ ​ ​ ​ ​ 15,928 ​ ​ 10,673 ​ Total deferred tax assets before valuation allowance ​ ​ ​ ​ ​ 411,952 ​ ​ 248,183 ​ Less: valuation allowance ​ ​ ​ ​ ​ (396,079) ​ ​ (222,521) ​ ​ ​ ​ ​ ​ ​ 15,873 ​ ​ 25,662 ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible debt ​ ​ ​ ​ ​ — ​ ​ (19,143) ​ Right-of-use lease assets ​ ​ ​ ​ ​ (15,873) ​ ​ (6,519) ​ Net deferred tax assets ​ ​ ​ ​ $ — ​ $ — ​ ​ The Company established a full valuation allowance against its net deferred tax assets in 2021 and 2020 due to the uncertainty surrounding realization of these assets. The valuation allowance increased to $396.1 million as of December 31, 2021 from $222.5 million as of December 31, 2020 due to current year losses and credits claimed. ​ As of December 31, 2021, the Company had federal, state, and foreign net operating loss (“NOLs”) carryforwards of approximately $1.3 billion, $796.7 million, and $4.0 million, respectively, which begin to expire in 2027, 2028, and 2031, respectively, if not utilized. Approximately $950.2 million of federal net operating loss included above can be carried forward indefinitely. ​ The Company also had federal research and development credit carryforwards of approximately $34.5 million, which begin to expire in 2027, and state research and development credit carryforwards of approximately $23.0 million, which can be carried forward indefinitely. Realization of these deferred tax assets would require $1.5 billion in taxable income to fully utilize. Realization is dependent on generating sufficient taxable income prior to expiration of the loss and credit carryforwards. ​ Federal, state and foreign tax laws impose substantial restrictions on the utilization of NOLs and credit carryforwards in the event of an "ownership change" for tax purpose, as defined in Section 382 of the Internal Revenue Code. Accordingly, the Company's ability to utilize these carryforwards may be limited as the result of such ownership change. Such a limitation could result in limitation in the use of the NOLs in future years and possibly a reduction of the NOLs available. ​ A reconciliation of the beginning and ending amount of gross unrecognized tax benefits is as follows: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 2020 ​ 2019 ​ ​ (in thousands) ​ Balance at beginning of year ​ $ 11,500 ​ $ 8,619 ​ $ 7,362 ​ Additions based on tax positions related to the current year ​ ​ 6,017 ​ ​ 2,889 ​ ​ 1,426 ​ Additions (reductions) for tax positions of prior years ​ ​ (3) ​ ​ (8) ​ ​ (169) ​ Balance at end of year ​ $ 17,514 ​ $ 11,500 ​ $ 8,619 ​ ​ During the years ended December 31, 2021, 2020, and 2019, the amount of unrecognized tax benefits increased $6.0 million, $2.9 million, and $1.3 million, respectively, due to additional research and development credits generated during the year. As of December 31, 2021, 2020, and 2019, the total amount of unrecognized tax benefits was $17.5 million, $11.5 million, and $8.6 million, respectively. The reversal of the uncertain tax benefits would not affect the Company's effective tax rate to the extent that it continues to maintain a full valuation allowance against its deferred tax assets. ​ The Company is subject to U.S. federal, state, and foreign income taxes. Tax regulations within each jurisdiction are subject to the interpretation of the related tax laws and regulations, and require significant judgment to apply. The Company is subject to U.S. federal, state and local tax examinations by tax authorities for all prior tax years since incorporation. The Company does not anticipate significant changes to its current uncertain tax positions through December 31, 2022. ​ The Company recognizes any interest and/or penalties related to income tax matters as a component of income tax expense. As of December 31, 2021, there were no

Net Loss per Share

Net Loss per Share	12 Months Ended
	Dec. 31, 2021
Net Loss per Share
Net Loss per Share	14. Net Loss per Share ​ Basic net loss per share is computed by dividing the net loss attributable to common stockholders by the weighted-average number of common shares outstanding for the period, excluding shares subject to repurchase and without consideration of potentially dilutive securities. Diluted net loss per share is computed by giving effect to all potentially dilutive common shares outstanding for the period. For purposes of this computation, outstanding common stock options, and restricted stock units are considered to be common share equivalents. Common share equivalents are excluded from the computation in periods in which they have an anti-dilutive effect, unless the consideration of any one of them gives a dilutive effect. The Convertible Notes are convertible as of December 31, 2021. Upon conversion, the Company has the option to pay cash, issue shares of common stock, or any combination thereof for the aggregate amount due upon conversion. If converted, the value of the Convertible Notes based on contractual settlement provisions would exceed its principal amount by $441.9 million as of December 31, 2021. Since the Company is in a net loss position in the periods presented, the shares which would be issued upon conversion of the Convertible Notes are excluded from the net loss per share calculation as it would have an antidilutive effect. As such, the 7.4 million shares underlying the conversion option of the Convertible Notes will not have an impact on the Company’s diluted earnings per share. If converted, the Company does not intend to settle the obligation in cash. The following table provides the basic and diluted net loss per share computations for the years ended December 31, 2021, 2020, and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2021 ​ 2020 ​ 2019 ​ ​ (in thousands, except per share data) Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss used to compute net loss per share, basic and diluted ​ $ (471,716) ​ $ (229,743) ​ $ (124,827) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average number of shares used in computing net loss per share, basic and diluted ​ 90,558 ​ 81,011 ​ 69,555 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss per share, basic and diluted ​ $ (5.21) ​ $ (2.84) ​ $ (1.79) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The following table shows the potentially dilutive common stock equivalents that were excluded from the computations of diluted net loss per share as their effect would be anti-dilutive, as of December 31, 2021, 2020, and 2019: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 2020 2019 ​ (in thousands) ​ Options to purchase common stock ​ 5,898 6,707 8,497 ​ Restricted stock units ​ 3,988 ​ 4,188 ​ 2,404 ​ Employee stock purchase plan ​ 33 ​ 37 ​ 32 ​ Convertible Note ​ 7,411 ​ 7,411 ​ — ​ Estimated earnout shares for an asset acquisition ​ 353 ​ — ​ — ​ ​ ​ 17,683 18,343 ​ 10,933 ​ ​

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2021
Subsequent Events
Subsequent Events	15. Subsequent Events ​ None. ​

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Summary of Significant Accounting Policies
Basis of Presentation	Basis of Presentation ​ The accompanying consolidated financial statements have been prepared in conformity with U.S. generally accepted accounting principles (“U.S. GAAP”).
Liquidity Matters	Liquidity Matters ​ The Company has incurred net losses since its inception and anticipates net losses and negative operating cash flows for the near future. The Company had a net loss of $471.7 million for the year ended December 31, 2021 and an accumulated deficit of $1.4 billion as of December 31, 2021. As of December 31, 2021, the Company had $84.6 million in cash, cash equivalents, and restricted cash, $829.9 million in marketable securities, $50.1 million of outstanding balance of the Credit Line (as defined in Note 10, Debt) including accrued interest, and $287.5 million outstanding principal balance of its 2.25% Convertible Senior Notes (the “Convertible Notes”). In April 2020, the Company used a portion of the net proceeds from the offering of the Convertible Notes to repay its obligations under its 2017 Term Loan with OrbiMed. ​ While the Company has introduced multiple products that are generating revenues, these revenues have not been sufficient to fund all operations and business plans. Accordingly, the Company has funded the portion of its operating costs and business plans that exceed revenues through a combination of equity issuances, debt issuances, and other financings. The Company continues to invest in the development and commercialization of its existing and future products and, consequently, it will need to generate additional revenues to achieve future profitability and may need to raise additional equity or debt financing. If the Company raises additional funds by issuing equity securities, its stockholders will experience dilution. Additional debt financing, if available, may involve covenants restricting its operations or its ability to incur additional debt. Any additional debt financing or additional equity that the Company raises may contain terms that are not favorable to it or its stockholders and requires significant debt service payments, which diverts resources from other activities. Additional financing may not be available when necessary, or in amounts or on terms acceptable to the Company. If the Company is unable to obtain additional financing, it may be required to delay or slow its investment in the development and commercialization of its products and significantly scale back its business and operations. On September 10, 2021, the Company entered into an agreement with a third party for an asset acquisition where the acquired asset was in-process research and development primarily in exchange for an equity consideration payment. In addition, pursuant to the agreement, certain employees of the third party became employees of the Company. The third party was a biotechnology company focused on oncology. The total upfront acquisition consideration amounts to $35.6 million composed of the issuance of 276,346 shares of the Company's common stock with a fair value of $30.9 million, approximately $3.9 million of cash consideration, assumed net liabilities of $0.2 million, as well as $0.6 million of acquisition related legal and accounting costs directly attributable to the acquisition of the asset. The Company accounted for the transaction as an asset acquisition as substantially all of the estimated fair value of the gross assets acquired was concentrated in a single identified in-process research and development asset (“IPR&D”) thus satisfying the requirements of the screen test in ASU 2017-01. The estimated fair value of the acquired workforce was not significant. The Company concluded the acquired IPR&D has no alternative-future use and accordingly expensed approximately $35.6 million, on the day the transaction closed as research and development expense, which is reflected in its consolidated statement of operations. Further, additional consideration aggregating up to approximately $35.0 million may be paid in an estimated 269,547 of additional shares, consistent with the registration statement filed with the SEC on September 10, 2021, that are potentially issuable to legacy shareholders of this third party upon the achievement of defined milestones relating to product development, commercial launch and continued employment of certain selling shareholders, each of which will be revalued at each reporting date and amount of compensation expense will be adjusted accordingly. The Company assessed these milestones as probable as of September 30, 2021 and December 31, 2021. As achievement of all milestones is contingent upon the continued employment of certain selling shareholders, the Company accounted for the consideration related to all of the milestones as compensation expenses and recognized these expenses ratably over the estimated performance period of 24 months, to approximately August 2023. ​ In April 2019, the Company completed an underwritten equity offering and sold 6,052,631 shares of its common stock at a price of $19 per share to the public. Before offering expenses of $0.6 million, the Company received proceeds of $108.1 million net of the underwriting discount. In October 2019, the Company completed another underwritten equity offering and sold 6,571,428 shares of its common stock at a price of $35 per share to the public. Before offering expenses of $0.4 million, the Company received proceeds of $216.2 million net of the underwriting discount. In September 2020, the Company completed an additional underwritten equity offering and sold 4,791,665 shares of its common stock at a price of $60.00 per share to the public. Before offering expenses of $0.3 million, the Company received proceeds of $271.0 million net of the underwriting discount. In July 2021, the Company completed an underwritten equity offering and sold 5,175,000 shares of its common stock at a price of $113 per share to the public. Before offering expenses of $0.4 million, the Company received proceeds of $551.2 million net of the underwriting discount. Based on the Company’s current business plan, the Company believes that its existing cash and marketable securities will be sufficient to meet its anticipated cash requirements for at least 12 months after February 24, 2022.
Principles of Consolidation	Principles of Consolidation ​ The accompanying consolidated financial statements include all the accounts of the Company and its subsidiaries. The Company established a subsidiary that operates in the state of Texas to support the Company’s laboratory and operational functions. The Company established a subsidiary that operates in Canada following the acquisition of the IPR&D asset, which includes a lease for the laboratory space located in Canada. All intercompany balances and transactions have been eliminated.
Use of Estimates	Use of Estimates ​ ​ Revenue ​ ​ ​ Stock-based compensation ​ ​ ​ requisite service period in which the awards are expected to vest and forfeitures are estimated based on historical trends at the time of grant and revised as necessary. Stock option awards that include a service condition and a performance condition are considered expected to vest when the performance condition is probable of being met. The Black-Scholes model considers several variables and assumptions in estimating the fair value of stock-based awards. These variables include the per share fair value of the underlying common stock, exercise price, expected term, risk-free interest rate, expected annual dividend yield and the expected stock price volatility over the expected term. For all stock options granted, we calculate the expected term using the simplified method for “plain vanilla” stock option awards. We determine expected volatility using the historical volatility of the stock price of similar publicly traded peer companies. The risk-free interest rate is based on the yield available on U.S. Treasury zero-coupon issues similar in duration to the expected term of the equity-settled award. ​ ​ ​ ​ Income Taxes ​ Income Taxes Income Taxes ​ Allowance for doubtful accounts ​ ​ Financial Instruments—Credit Losses ​ Inventory ​ and scrapped inventory. Any write-down of inventory to net realizable value establishes a new cost basis and will be maintained even if certain circumstances suggest the inventory is recoverable in subsequent periods. Costs associated with the write-down of inventory are recorded to cost of revenue on our consolidated statements of operations. The Company makes assumptions about future demand, market conditions and the release of new products that may supersede older products. However, if actual market conditions are less favorable than anticipated, additional inventory write-downs may be required. ​ Investments and financial instruments ​ ​ Right-of-use assets ​ ​ Property and equipment ​ three years ​ Other accrued liabilities ​
Cash and Cash Equivalents	Cash and Cash Equivalents ​ Cash and cash equivalents consist of cash and money market deposits with financial institutions.
Restricted Cash	Restricted Cash ​ Restricted cash is currently presented as a separate line item in the Company’s balance sheet. In the statements of cash flows, it is included together with cash and cash equivalents and considered as part of the total ending cash balance. The following is the reconciliation between how restricted cash is presented in the balance sheet and the statements of cash flows for all periods presented: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 ​ ​ (in thousands) Cash and cash equivalents in balance sheet ​ $ 84,386 ​ $ 48,668 Restricted cash, current portion in balance sheet ​ ​ 228 ​ ​ 187 Total cash, cash equivalents and restricted cash in statements of cash flows ​ $ 84,614 ​ $ 48,855
Investments	Investments Investments consist primarily of debt securities such as U.S. Treasuries, U.S. agency and municipal bonds. Management determines the appropriate classification of securities at the time of purchase and re-evaluates such determination at each balance sheet date. The Company generally classifies its entire investment portfolio as available-for-sale. The Company views its available-for-sale portfolio as available for use in current operations. Accordingly, the Company classifies all investments as short-term, irrespective of maturity date. Available-for-sale securities are carried at fair value, with unrealized gains and losses reported in accumulated other comprehensive income (loss), which is a separate component of stockholders’ equity. ​ On December 6, 2021, the Company participated along with certain other investors in the series B financing of MyOme, Inc. (“MyOme”), and purchased preferred shares and warrants in exchange for approximately $4.0 million cash payment. Matthew Rabinowitz is the Chairman of the board of directors and Co-Founder of both the Company and MyOme. The Company’s investment in MyOme is recorded at cost and will be evaluated for impairment at the end of each reporting period.
Fair Value	Fair Value ​ The Company discloses the fair value of financial instruments for financial assets and liabilities for which the value is practicable to estimate. Fair value is defined as the price that would be received upon the sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date (exit price).
Risk and Uncertainties	Risk and Uncertainties ​ The Company is subject to risks and uncertainties as a result of the COVID-19 pandemic. The extent of the impact of the COVID-19 pandemic on the Company's business is highly uncertain and difficult to predict, and the full extent and duration of the impact of the COVID 19 pandemic on our business, our operations, and the global economy as a whole is not yet known. While the Company’s test volumes as well as overall average selling prices increased in the year ended December 31, 2021 compared to the year ended December 31, 2020, the Company cannot predict the potential nature, magnitude and duration of the effects of the COVID-19 pandemic on the macroeconomic environment. Financial instruments that potentially subject the Company to credit risk consist of cash, accounts receivable and investments. The Company limits its exposure to credit loss by placing its cash in financial institutions with high credit ratings. The Company's cash may consist of deposits held with banks that may at times exceed federally insured limits. The Company performs evaluations of the relative credit standing of these financial institutions and limits the amount of credit exposure with any one institution. The Company performs evaluations of financial conditions for insurance carriers, patients, clinics and laboratory partners and generally does not require collateral to support credit sales. For the years ended December 31, 2021, 2020, and 2019, there were no customers exceeding 10% of total revenues on an individual basis. As of December 31, 2021 and 2020, there were no customers with an outstanding balance exceeding 10% of net accounts receivable.
Credit Losses	Credit Losses ​ Trade accounts receivable and other receivables. ​ The following is a roll-forward of the allowances for credit losses related to trade accounts receivable and other receivables for the year ended December 31, 2021: ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ ​ (in thousands) Beginning balance ​ $ 4,220 Provision for credit losses ​ ​ (156) Write-offs ​ ​ (1,635) Total ​ $ 2,429 ​ Available-for-sale debt securities. The amended guidance from ASU 2016-13 requires the measurement of expected credit losses for available-for-sale debt securities held at the reporting date over the remaining life based on historical experience, current conditions, and reasonable and supportable forecasts. The Company evaluated its investment portfolio under the new available-for-sale debt securities impairment model guidance. The vast majority of the Company’s investment portfolio are low risk, investment grade securities.
Revenue Recognition	Revenue Recognition ​ The Company adopted the new revenue recognition guidance, ASC 606, beginning January 1, 2018 on a full retrospective basis. ASC 606 mandates revenue recognition to be evaluated using the following five steps: ​ ● Identification of a contract, or contracts, with a customer; ● Identification of the performance obligations in the contract; ● Determination of the transaction price; ● Allocation of the transaction price to the performance obligations in the contract; and ● Revenue recognition when, or as, the performance obligations are satisfied ​ Revenue Recognition,
Cost of Product Revenues	Cost of Product Revenues ​ The components of our cost of product revenues are material and service costs, impairment charges associated with testing equipment, personnel costs, including stock-based compensation expense, equipment and infrastructure expenses associated with testing samples, electronic medical records, order and delivery systems, shipping charges to transport samples, costs incurred from third party test processing fees, and allocated overhead such as rent, information technology costs, equipment depreciation and utilities. Costs associated with Whole Exome Sequencing (“WES”) are also included, as well as labor costs, relating to our Signatera CLIA offering. Costs associated with performing tests are recorded when the test is accessioned. We expect cost of product revenues in absolute dollars to increase as the number of tests we perform increases. ​
Cost of Licensing and Other Revenues	Cost of Licensing and Other Revenues ​ The components of our cost of licensing and other revenues are material costs associated with test kits sold to Constellation clients, development and support services relating to our Strategic Partnership Agreements, and costs associated with specimens and Whole Exome Sequencing (“WES”), as well as labor costs, relating to our Signatera (RUO) and CDx offering. ​ We consider our cost of licensing and other revenues for the Constellation software platform to be relatively low, and therefore we expect its associated gross margin is higher. We expect our cost of licensing will increase in relation to volume growth.
Research and Development	Research and Development ​ The Company records research and development costs in the period incurred. Research and development costs consist of personnel costs, contract services, cost of materials utilized in performing tests, costs of clinical trials and allocated facilities and related overhead expenses.
Advertising Costs	Advertising Costs ​ The Company expenses advertising costs as incurred. The Company incurred advertising costs of $2.2 million, $0.6 million, and $0.2 million for the years ended December 31, 2021, 2020, and 2019, respectively.
Product Shipment Costs	Product Shipment Costs ​ The Company expenses product shipment costs in cost of product revenues in the accompanying statements of operations. Shipping and handling costs for the years ended December 31, 2021, 2020, and 2019 were $22.0 million, $13.3 million, and $13.3 million, respectively.
Income Taxes	Income Taxes ​ Income taxes are recorded in accordance with Financial Accounting Standards Board ASC Topic 740, Income Taxes
Stock-Based Compensation	Stock-Based Compensation ​ Stock-based compensation related to stock options and restricted stock units (“RSUs”) granted to the Company’s employees is measured at the grant date based on the fair value of the award. The fair value is recognized as expense over the requisite service period, which is generally the vesting period of the respective awards. No compensation cost is recognized when the requisite service has not been met and the awards are therefore forfeited. ​ For stock options with market conditions, the Company derives the requisite service period using the Monte Carlo simulation model. For stock options and RSUs that vest upon meeting performance conditions or market conditions in combination with performance conditions, the Company derives the requisite service period from the grant date to the date it is probable that the vesting conditions will be met. ​
Capitalized Software Held for Internal Use	Capitalized Software Held for Internal Use ​ The Company capitalizes salaries and related costs of employees and consultants who devote time to the development of internal-use software development projects. Capitalization begins during the application development stage, once the preliminary project stage has been completed, which includes successful validation and approval from management. If a project constitutes an enhancement to previously developed software, the Company assesses whether the enhancement is significant and creates additional functionality to the software, thus qualifying the work incurred for capitalization. Once the project is available for general release, capitalization ceases and the Company estimates the useful life of the asset and begins amortization. The Company periodically assesses whether triggering events are present to review internal-use software for impairment. Changes in estimates related to internal-use software would increase or decrease operating expenses or amortization recorded during the reporting period. ​ The Company amortizes its internal-use software over the estimated useful lives of three years. The net book value of capitalized software held for internal use was $2.3 million and $1.7 million as of December 31, 2021 and 2020, respectively. Amortization expense for amounts previously capitalized for the years ended December 31, 2021, 2020, and 2019, was $1.1 million, $1.0 million, and $1.2 million, respectively.
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Comprehensive loss and its components encompass all changes in equity other than those with stockholders, and include net loss, and unrealized gains and losses on available-for-sale marketable securities. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ ​ (in thousands) Beginning balance ​ $ 4,259 ​ $ 919 Net unrealized gains (losses) on available-for-sale securities, net of tax ​ ​ (6,546) ​ ​ 3,340 Ending balance ​ $ (2,287) ​ $ 4,259 ​ ​ ​ ​ ​ ​ ​
Property and Equipment	Property and Equipment ​ Property and equipment, including purchased and internally developed software, are stated at cost. Depreciation is calculated using the straight-line method over the estimated useful lives of the assets, which are generally three five or the remaining term of the lease, whichever is shorter. The Company periodically reviews the depreciable lives assigned to property and equipment placed in service and change the estimates of useful lives to reflect the results of such reviews.
Impairment of Long-lived Assets	Impairment of Long-lived Assets ​ The Company evaluates its long-lived assets for indicators of possible impairment when events or changes in circumstances indicate the carrying amount of an asset may not be recoverable. The Company then compares the carrying amounts of the assets with the future net undiscounted cash flows expected to be generated by such asset. Should an impairment exist, the impairment loss would be measured based on the excess carrying value of the asset over the asset’s fair value determined using discounted estimates of future cash flows.
Inventory	Inventory ​ Inventory is valued at the lower of the standard cost, which approximates actual cost, or market. Cost is determined using the first-in, first-out (“FIFO”) method. Inventory consists entirely of supplies, which are consumed when providing its test reports, and therefore does not maintain any finished goods inventory. The Company enters into inventory purchases and commitments so that it can meet future delivery schedules based on forecasted demand for its tests. ​ The Company recorded inventory obsolescence charges totaling $0.9 million, $0.2 million, and $0.3 million, in the years ended December 31, 2021, 2020, and 2019, respectively. ​
Recent Accounting Pronouncements	Recent Accounting Pronouncements ​ From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (the “FASB”) under its accounting standard codifications (“ASC”) or other standard setting bodies and adopted by the Company as of the specified effective date. Unless otherwise discussed below, the Company believes that the impact of recently issued standards that are not yet effective will not have a material impact on its financial position or results of operations upon adoption. ​ Recently Adopted Accounting Pronouncements ​ Income Taxes Codification Improvements Debt In August 2020, ASU 2020-06, Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40) cumulative effect of the change was recognized as an adjustment to the opening balance of retained earnings at the date of adoption. The comparative information has not been restated and continues to be presented according to accounting standards in effect for those periods. This adjustment was calculated based on the carrying amount of the Convertible Notes as if it had always been treated only as a liability. Further, an adjustment was recorded to the debt discount and issuance costs as if these had always been treated as a contra liability only. Interest expense related to the accretion of the Convertible Notes is no longer recognized. Interest expense for the Convertible Notes for the year ended December 31, 2021 would have been $9.4 million higher without the adoption of ASU 2020-06. As such, net loss from continuing operations attributable to the Company for the year ended December 31, 2021 was $0.10 per common share lower due to the effect of adoption of ASU 2020-06. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ASU 2020-06 ​ January 1, ​ 2020 ​ Adoption Adjustment ​ 2021 ​ (in thousands) Liabilities ​ ​ ​ ​ ​ ​ ​ ​ Outstanding Principal $ 287,500 ​ $ — ​ $ 287,500 Unamortized debt discount and issuance cost ​ (85,007) ​ ​ 76,674 ​ ​ (8,333) Net carrying amount $ 202,493 ​ $ 76,674 ​ $ 279,167 ​ ​ ​ ​ ​ ​ ​ ​ ​ Equity ​ ​ ​ ​ ​ ​ ​ ​ Additional paid-in-capital $ (1,411,286) ​ $ 82,876 ​ $ (1,328,410) Accumulated deficit ​ (929,318) ​ ​ 6,198 ​ ​ (923,120) ​ ​ New Accounting Pronouncements Not Yet Adopted In March 2020, ASU 2020-04, Reference Rate Reform (Topic 848)

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Summary Of Significant Accounting Policies [Line Items]
Schedule of reconciliation of restricted cash	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ 2021 2020 ​ ​ (in thousands) Cash and cash equivalents in balance sheet ​ $ 84,386 ​ $ 48,668 Restricted cash, current portion in balance sheet ​ ​ 228 ​ ​ 187 Total cash, cash equivalents and restricted cash in statements of cash flows ​ $ 84,614 ​ $ 48,855
Schedule of allowances for credit losses related to trade accounts receivable and other receivables	​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ ​ (in thousands) Beginning balance ​ $ 4,220 Provision for credit losses ​ ​ (156) Write-offs ​ ​ (1,635) Total ​ $ 2,429
Schedule of allowances for credit losses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ December 31, ​ 2021 ​ 2020 ​ 2019 ​ (in thousands) Beginning balance $ 4,220 ​ $ 2,919 ​ $ 1,788 Cumulative-effect adjustment upon adoption of ASU 2016-13 ​ — ​ ​ 404 ​ ​ — Provision for credit losses ​ (156) ​ ​ 1,354 ​ ​ 1,141 Write offs ​ (1,635) ​ ​ (457) ​ ​ (10) Ending balance $ 2,429 ​ $ 4,220 ​ $ 2,919 ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of Accumulated Other Comprehensive Income (Loss)	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ ​ (in thousands) Beginning balance ​ $ 4,259 ​ $ 919 Net unrealized gains (losses) on available-for-sale securities, net of tax ​ ​ (6,546) ​ ​ 3,340 Ending balance ​ $ (2,287) ​ $ 4,259 ​ ​ ​ ​ ​ ​ ​
Accounting Standards Update 2020-06
Summary Of Significant Accounting Policies [Line Items]
Schedule of new accounting pronouncements and changes in accounting principle	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ASU 2020-06 ​ January 1, ​ 2020 ​ Adoption Adjustment ​ 2021 ​ (in thousands) Liabilities ​ ​ ​ ​ ​ ​ ​ ​ Outstanding Principal $ 287,500 ​ $ — ​ $ 287,500 Unamortized debt discount and issuance cost ​ (85,007) ​ ​ 76,674 ​ ​ (8,333) Net carrying amount $ 202,493 ​ $ 76,674 ​ $ 279,167 ​ ​ ​ ​ ​ ​ ​ ​ ​ Equity ​ ​ ​ ​ ​ ​ ​ ​ Additional paid-in-capital $ (1,411,286) ​ $ 82,876 ​ $ (1,328,410) Accumulated deficit ​ (929,318) ​ ​ 6,198 ​ ​ (923,120)

Revenue Recognition (Tables)

Revenue Recognition (Tables)	12 Months Ended
	Dec. 31, 2021
Revenue Recognition
Schedule of disaggregation of revenues by payer types	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year Ended December 31, ​ ​ 2021 ​ 2020 ​ 2019 ​ ​ (in thousands) Insurance carriers ​ $ 492,563 ​ $ 300,220 ​ $ 210,919 Laboratory partners ​ ​ 100,019 ​ ​ 58,196 ​ ​ 59,876 Patients ​ ​ 32,904 ​ ​ 32,589 ​ ​ 31,533 Total revenues ​ $ 625,486 ​ $ 391,005 ​ $ 302,328
Schedule of total revenue by geographic area	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2021 2020 2019 ​ ​ (in thousands) United States ​ $ 590,872 $ 365,660 $ 260,846 Americas, excluding U.S. ​ ​ 4,047 ​ 3,469 ​ 3,218 Europe, Middle East, India, Africa ​ ​ 20,429 ​ 14,332 ​ 15,434 Asia Pacific and Other ​ ​ 10,138 ​ 7,544 ​ 22,830 Total ​ $ 625,486 $ 391,005 ​ $ 302,328
Schedule of beginning and ending balances of accounts receivable and deferred revenues	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at ​ Balance at ​ ​ December 31, ​ December 31, ​ ​ 2021 ​ 2020 ​ ​ (in thousands) Assets: ​ ​ ​ ​ ​ ​ Accounts receivable ​ $ 122,074 ​ $ 78,565 Liabilities: ​ ​ ​ ​ ​ ​ Deferred revenue, current portion ​ $ 7,404 ​ $ 50,125 Deferred revenue, long-term portion ​ ​ 21,318 ​ ​ 22,805 Total deferred revenues ​ $ 28,722 ​ $ 72,930
Schedule of changes in the balance of deferred revenues	​ ​ ​ ​ ​ ​ ​ Deferred ​ ​ Revenues ​ ​ (in thousands) Balance at December 31, 2020 ​ $ 72,930 Increase in deferred revenues ​ ​ 7,915 Reclasses from deferred revenues to other to short-term liabilities ​ ​ (10,080) Revenue recognized during the period that was included in ​ ​ (37,784) Revenue recognized from performance obligations satisfied ​ ​ (4,259) Balance at December 31, 2021 ​ $ 28,722
Schedule of insurance carrier reserve balance	​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ 2021 2020 ​ ​ (in thousands) Beginning balance ​ $ 17,366 ​ $ 9,410 Additional reserves ​ ​ 16,340 ​ ​ 19,427 Refunds to carriers ​ ​ (10,784) ​ ​ (6,066) Reserves released to revenue ​ ​ (5,712) ​ ​ (5,405) Ending balance ​ $ 17,210 ​ $ 17,366 ​ ​ ​ ​ ​ ​ ​

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Measurements
Summary of financial assets and liabilities measured on recurring basis	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ December 31, 2020 ​ Level I Level II Level III Total Level I Level II Level III Total ​ ​ (in thousands) Financial Assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Money market deposits ​ $ 10,041 ​ $ — ​ $ — ​ $ 10,041 ​ $ 28,990 ​ $ — ​ $ — ​ $ 28,990 ​ U.S. Treasury securities ​ ​ 688,097 ​ ​ — ​ ​ — ​ ​ 688,097 ​ ​ 597,744 ​ ​ — ​ ​ — ​ ​ 597,744 ​ Corporate bonds and notes ​ ​ — ​ ​ 52,337 ​ ​ — ​ ​ 52,337 ​ ​ — ​ ​ 12,328 ​ ​ — ​ ​ 12,328 ​ Municipal securities ​ ​ — ​ ​ 89,462 ​ ​ — ​ ​ 89,462 ​ ​ — ​ ​ 78,534 ​ ​ — ​ ​ 78,534 ​ Total financial assets ​ $ 698,138 ​ $ 141,799 ​ $ — ​ $ 839,937 ​ $ 626,734 ​ $ 90,862 ​ $ — ​ $ 717,596 ​

Financial Instruments (Tables)

Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2021
Financial Instruments
Schedule of available-for-sale securities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ December 31, 2020 ​ Amortized Cost Gross Unrealized Gain Gross Unrealized (Loss) Estimated Fair Value Amortized Cost Gross Unrealized Gain Gross Unrealized (Loss) Estimated Fair Value ​ ​ (in thousands) Money market deposits ​ $ 10,041 ​ $ — ​ $ — ​ $ 10,041 ​ $ 28,990 ​ $ — ​ $ — ​ $ 28,990 ​ U.S. Treasury securities (1) ​ 689,640 ​ 1,081 ​ (2,624) ​ 688,097 ​ 594,252 ​ 3,512 ​ (20) ​ 597,744 ​ Corporate bonds and notes (1) ​ 52,729 ​ — ​ (392) ​ 52,337 ​ 12,331 ​ 2 ​ (5) ​ 12,328 ​ Municipal securities ​ ​ 89,814 ​ ​ 261 ​ ​ (613) ​ ​ 89,462 ​ ​ 77,764 ​ ​ 796 ​ ​ (26) ​ ​ 78,534 ​ Total ​ $ 842,224 ​ $ 1,342 ​ $ (3,629) ​ $ 839,937 ​ $ 713,337 ​ $ 4,310 ​ $ (51) ​ $ 717,596 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Classified as: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Cash equivalents (2) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 10,041 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 28,990 ​ Short-term investments ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 829,896 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 688,606 ​ Total ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 839,937 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ $ 717,596 ​ ​ (1) Per the Company’s investment policy, all debt securities are classified as short-term investments irrespective of holding period. (2) Cash equivalents includes cash sweep accounts and U.S. Treasury money market mutual funds.
Summarized portfolio of available-for-sale securities by contractual maturity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ Amortized Cost ​ Fair Value ​ ​ ​ (in thousands) ​ Less than or equal to one year ​ $ 274,879 ​ $ 275,331 ​ Greater than one year but less than five years ​ ​ 557,304 ​ ​ 554,565 ​ Total ​ $ 832,183 ​ $ 829,896 ​

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2021
Balance Sheet Components
Schedule of allowances for credit losses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ December 31, ​ 2021 ​ 2020 ​ 2019 ​ (in thousands) Beginning balance $ 4,220 ​ $ 2,919 ​ $ 1,788 Cumulative-effect adjustment upon adoption of ASU 2016-13 ​ — ​ ​ 404 ​ ​ — Provision for credit losses ​ (156) ​ ​ 1,354 ​ ​ 1,141 Write offs ​ (1,635) ​ ​ (457) ​ ​ (10) Ending balance $ 2,429 ​ $ 4,220 ​ $ 2,919 ​ ​ ​ ​ ​ ​ ​ ​ ​
Schedule of property and equipment	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ December 31, ​ ​ Useful Life 2021 2020 ​ ​ ​ ​ ​ (in thousands) ​ Machinery and equipment 3-5 years $ 33,722 ​ $ 51,001 ​ Furniture and fixtures 3 years ​ — ​ 1,376 ​ Computer equipment 3 years ​ 4,893 ​ 2,428 ​ Capitalized software held for internal use ​ 3 years ​ ​ 2,395 ​ ​ 7,417 ​ Leasehold improvements Life of lease ​ 13,640 ​ 14,810 ​ Construction-in-process ​ ​ ​ 30,279 ​ 6,370 ​ ​ ​ ​ ​ 84,929 ​ 83,402 ​ Less: Accumulated depreciation and amortization ​ ​ ​ (19,413) ​ (50,054) ​ Total Property and Equipment, net ​ ​ ​ $ 65,516 ​ $ 33,348 ​
Schedule of accrued compensation	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ ​ 2021 2020 ​ ​ (in thousands) ​ Accrued paid time off ​ $ 2,567 ​ $ 2,260 ​ Accrued commissions ​ 15,726 ​ 12,686 ​ Accrued bonuses ​ 15,854 ​ 9,635 ​ Other accrued compensation ​ 6,794 ​ 5,790 ​ Total accrued compensation ​ $ 40,941 ​ $ 30,371 ​
Schedule of other accrued liabilities	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ 2021 2020 ​ ​ (in thousands) Reserves for refunds to insurance carriers ​ $ 17,210 ​ $ 17,366 ​ Accrued charges for third-party testing ​ ​ 5,849 ​ ​ 5,141 ​ Testing and laboratory materials from suppliers ​ ​ 3,799 ​ ​ 2,720 ​ Marketing and corporate affairs ​ ​ 7,853 ​ ​ 3,325 ​ Legal, audit and consulting fees ​ ​ 11,758 ​ ​ 4,189 ​ Accrued shipping charges ​ ​ 969 ​ ​ 1,604 ​ Sales tax payable ​ ​ 2,230 ​ ​ 1,723 ​ Accrued third-party service fees ​ ​ 13,442 ​ ​ 2,355 ​ Clinical trials, studies, and other development ​ 11,218 ​ 2,353 ​ Operating lease liabilities, current portion ​ ​ 5,752 ​ ​ 7,300 ​ Fixed asset purchases ​ ​ 1,853 ​ ​ 1,691 ​ Other accrued interest ​ ​ 1,078 ​ ​ 1,078 ​ Other accrued expenses ​ 10,342 ​ 9,562 ​ Total other accrued liabilities ​ $ 93,353 ​ $ 60,407 ​

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2021
Leases.
Schedule of lease liabilities	​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ (in thousands) Operating lease liabilities, current portion included in other accrued liabilities ​ $ 5,752 Operating lease liabilities, long-term portion ​ ​ 61,036 Total operating lease liabilities ​ $ 66,788
Schedule of annual minimum lease payments	​ ​ ​ ​ ​ ​ ​ Operating Leases ​ ​ (in thousands) Year ending December 31: ​ ​ ​ ​ 2022 ​ $ 9,980 ​ 2023 ​ ​ 11,082 ​ 2024 ​ ​ 12,258 ​ 2025 ​ ​ 12,494 ​ 2026 ​ ​ 12,845 ​ 2027 and thereafter ​ ​ 27,331 ​ Total future minimum lease payments ​ ​ 85,990 ​ Less: imputed interest ​ ​ (19,202) ​ Operating lease liabilities ​ $ 66,788 ​

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies
Schedule of material contractual commitments	​ ​ ​ ​ Party Total Commitments Expiry Date ​ ​ (in thousands) ​ Material suppliers $ 16,040 June 2026 Application service providers ​ 35,279 March 2026 Earnouts for development with third party (1) ​ 35,000 September 2023 Software development provider ​ 4,463 December 2024 Leases (2) ​ 29,683 March 2033 Other material suppliers ​ 17,510 Various Total ​ 137,975 ​ ​ ​ ​ ​ (1) The earnouts for asset development with the acquired Canadian entity consists of three milestones which are achieved upon the satisfaction of certain contractual conditions. Upon achievement, the earnout consideration will primarily be paid in the Company’s common stock.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Summary of offering activity	​ ​ ​ ​ ​ ​ ​ ​ ​ Number of ​ Total ​ ​ Shares Purchased ​ Proceeds Offering Period ​ (in thousands) November 1, 2019 - April 30, 2020 ​ 97,247 ​ $ 3,062 May 1, 2020 - October 31, 2020 ​ 136,288 ​ $ 4,052 November 1, 2020 - April 30, 2021 ​ 106,435 ​ $ 6,085 May 1, 2021 - October 31, 2021 ​ 79,820 ​ $ 7,465
Schedule of performance-based awards	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Period Granted ​ Options Granted ​ RSUs Granted ​ Options Vested ​ RSUs Vested ​ Milestone ​ Valuation Method (in thousands) Q1 2019 ​ 200 ​ 300 ​ 200 ​ 300 ​ (1) ​ Monte-Carlo Simulation Q2 2019 ​ — ​ 188 ​ — ​ 81 ​ (2) ​ Fair Market Value Q3 2019 ​ — ​ 50 ​ — ​ 50 ​ (1) ​ Monte-Carlo Simulation Q1 2020 ​ 150 ​ 300 ​ 130 ​ 289 ​ (1) ​ Monte-Carlo Simulation Q1 2020 ​ — ​ 436 ​ — ​ 408 ​ (3) ​ Fair Market Value Q1 2020 ​ 129 ​ — ​ 129 ​ — ​ (3) ​ Black-Scholes-Merton Q2 2020 ​ — ​ 21 ​ — ​ 21 ​ (3) ​ Fair Market Value Q3 2020 ​ 10 ​ — ​ 10 ​ — ​ (4) ​ Black-Scholes-Merton Q3 2020 ​ — ​ 27 ​ — ​ 17 ​ (3) ​ Fair Market Value Q4 2020 ​ — ​ 32 ​ — ​ 19 ​ (1) ​ Monte-Carlo Simulation Q4 2020 ​ — ​ 22 ​ — ​ 2 ​ (5) ​ Fair Market Value Q1 2021 ​ 150 ​ 125 ​ — ​ — ​ (1) ​ Monte-Carlo Simulation Q1 2021 ​ — ​ 279 ​ — ​ 10 ​ (3) ​ Fair Market Value Q2 2021 ​ 163 ​ — ​ — ​ — ​ (1) ​ Monte-Carlo Simulation Q2 2021 ​ 29 ​ — ​ — ​ — ​ (3) ​ Black-Scholes-Merton Q2 2021 ​ — ​ 7 ​ — ​ — ​ (3) ​ Fair Market Value Q4 2021 ​ — ​ 20 ​ — ​ — ​ (1) ​ Monte-Carlo Simulation Q4 2021 ​ — ​ 205 ​ — ​ — ​ (3) ​ Fair Market Value ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ (1) The awards vest based on the achievement of certain values of the Company’s common stock at multiple thresholds within certain periods and are contingent upon the completion of requisite service through the date of such vesting. (2) The vesting of the awards will be triggered after the end of the achievement milestone, as measured by the Company. (3) The awards vest based on achievement of certain revenue targets, units, and system implementation, contingent upon the completion of requisite service through the date of such vesting. (4) The awards have vested based on a change of coverage. (5) The awards will vest based on achievement of certain revenue and recruiting targets.
Summary of stock option activity	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Outstanding Options ​ ​ ​ ​ Weighted- ​ ​ ​ ​ ​ ​ ​ Weighted- ​ Average ​ ​ ​ ​ Shares ​ ​ ​ Average ​ Remaining ​ Aggregate ​ ​ Available for ​ Number of ​ Exercise ​ Contractual ​ Intrinsic ​ ​ Grant ​ Shares ​ Price ​ Life ​ Value (in thousands, except for contractual life and exercise price) ​ ​ ​ ​ ​ ​ ​ ​ (in years) ​ ​ Balance at December 31, 2020 3,148 6,707 ​ $ 11.19 6.04 ​ $ 592,468 ​ Additional shares authorized 3,446 ​ — ​ $ — ​ ​ ​ ​ ​ ​ Options granted (391) 391 ​ $ 104.03 ​ ​ ​ ​ ​ ​ Options exercised — (1,165) ​ $ 10.14 ​ ​ ​ ​ ​ ​ Options forfeited/cancelled 33 (33) ​ $ 15.00 ​ ​ ​ ​ ​ ​ RSUs granted ​ (2,208) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ RSUs forfeited/cancelled ​ 291 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance at December 31, 2021 4,319 5,900 ​ $ 17.54 5.40 ​ $ 451,505 ​ Exercisable at December 31, 2021 ​ ​ 4,977 ​ $ 10.65 4.90 ​ $ 411,841 ​ Vested and expected to vest at December 31, 2021 ​ ​ 5,840 ​ $ 17.17 5.37 ​ $ 449,026 ​
Restricted stock units	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted- ​ ​ ​ ​ Average ​ ​ Number of ​ Grant Date ​ ​ Shares ​ Fair Value ​ ​ (in thousands) ​ ​ ​ Balance at December 31, 2020 ​ 4,188 ​ $ 34.02 Granted ​ 2,208 ​ $ 106.74 Vested ​ (2,117) ​ $ 29.46 Canceled/Forfeited ​ (291) ​ $ 55.16 Balance at December 31, 2021 3,988 ​ $ 74.33 ​ ​ ​ ​ ​ ​
Summary of stock-based compensation expenses	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ ​ 2021 ​ 2020 ​ 2019 ​ Employee Non-Employee Total Employee Non-Employee Total Employee Non-Employee Total ​ (in thousands) ​ Cost of revenues ​ $ 4,811 ​ $ — ​ $ 4,811 ​ $ 1,691 ​ $ — ​ $ 1,691 ​ $ 905 ​ $ 32 ​ $ 937 ​ Research and development ​ 24,507 ​ 1,361 ​ 25,868 ​ 10,777 ​ 647 ​ 11,424 ​ ​ 5,354 ​ — ​ 5,354 ​ Selling, general and administrative ​ 84,368 ​ 172 ​ 84,540 ​ 36,747 ​ 309 ​ 37,056 ​ ​ 21,730 ​ 603 ​ 22,333 ​ Total ​ $ 113,686 ​ $ 1,533 ​ $ 115,219 ​ $ 49,215 ​ $ 956 ​ $ 50,171 ​ $ 27,989 ​ $ 635 ​ $ 28,624 ​
Performance-based awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of assumptions used in valuation of fair value	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, December 31, ​ 2021 2020 Risk-free interest rate ​ 0.80 % — 1.52 % ​ 0.54 % — 1.64 % Expected dividend yield ​ ​ ​ ​ — ​ ​ ​ ​ ​ — ​ Expected volatility ​ ​ ​ ​ 60 % ​ 55 ​ ​ 65 % Expected term (years) ​ 7.25 ​ — 10.0 ​ ​ 5.25 ​ — 7.25 ​
Employee stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of assumptions used in valuation of fair value	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Year ended December 31, ​ 2021 2020 2019 ​ Expected term (years) 5.11 ​ — 10.00 ​ ​ 5.22 ​ — 10.00 ​ ​ 5.23 ​ — 10.00 ​ Expected volatility 55.33 % — 63.30 % 49.94 % — 61.96 % ​ 42.53 % — 45.84 % Expected dividend rate ​ ​ ​ 0 % ​ ​ ​ 0 % ​ ​ ​ ​ 0 % Risk-free interest rate 0.81 % — 1.67 % 0.31 % — 1.70 % ​ 1.60 % — 2.60 %

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2021
Debt
Schedule of outstanding Convertible Notes	​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ ​ (in thousands) ​ Liability Component ​ ​ ​ Outstanding Principal $ 287,500 ​ Unamortized debt discount and debt issuance cost ​ (7,106) ​ Net carrying amount $ 280,394 ​
Summary of interest expense	​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ 2021 ​ (in thousands) Cash interest expense ​ ​ ​ Contractual interest expense $ 6,469 ​ Non-cash interest expense ​ ​ ​ Amortization of debt discount and debt issuance cost ​ 1,227 ​ Total interest expense $ 7,696 ​

Disposal of Business (Tables)

Disposal of Business (Tables)	12 Months Ended
	Dec. 31, 2021
Disposal of Business
Schedule of computation of the gain realized from the disposal of business	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2019 ​ ​ ​ ​ ​ (in thousands) ​ ​ ​ ​ ​ ​ ​ Proceeds on disposal: ​ ​ ​ ​ $ 15,377 Assets sold: ​ ​ ​ ​ ​ ​ Accounts receivable, net ​ ​ ​ ​ ​ 5,782 Equipment and inventory ​ ​ ​ ​ ​ 419 Total assets sold ​ ​ ​ ​ $ 6,201 Liabilities assumed by purchaser: ​ ​ ​ ​ ​ ​ Deferred revenues ​ ​ ​ ​ ​ 5,212 Net assets and liabilities sold ​ ​ ​ ​ $ 989 Net gain realized on disposal ​ ​ ​ ​ $ 14,388

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Taxes
Schedule of effective tax rates differing from U.S. federal statutory rate	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 ​ 2020 ​ 2019 ​ ​ ​ (in thousands, except percentages) ​ U.S. federal taxes (benefit) at statutory rate ​ $ (98,931) ​ (21.00) % ​ $ (48,226) ​ (21.00) % ​ $ (25,794) (21.00) % State tax expense ​ ​ (29,206) ​ (6.20) % ​ ​ (10,672) ​ (4.65) % ​ ​ (6,607) ​ (5.38) % Research and development credits ​ ​ (9,193) ​ (1.95) % ​ ​ (3,964) ​ (1.73) % ​ ​ (1,645) ​ (1.34) % Stock-based compensation ​ ​ (46,128) ​ (9.80) % ​ ​ (23,791) ​ (10.36) % ​ ​ (7,544) ​ (6.14) % Foreign tax ​ ​ 167 ​ 0.04 % ​ ​ 55 ​ 0.02 % ​ ​ 1,612 ​ 1.31 % Other nondeductible items ​ ​ 344 ​ 0.07 % ​ ​ 792 ​ 0.35 % ​ ​ 769 ​ 0.63 % Nondeductible officers' compensation ​ ​ 24,387 ​ 5.18 % ​ ​ 8,984 ​ 3.91 % ​ ​ 609 ​ 0.50 % Acquisition costs ​ ​ 8,901 ​ 1.89 % ​ ​ — ​ — % ​ ​ — ​ — % Change in valuation allowance ​ ​ 150,277 ​ 31.90 % ​ ​ 76,920 ​ 33.50 % ​ ​ 40,599 ​ 33.05 % Provision for income taxes ​ $ 618 ​ 0.13 % ​ $ 98 ​ 0.04 % ​ $ 1,999 ​ 1.63 %
Schedule of tax effects of temporary differences that give rise to significant portions of the deferred tax assets	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ ​ 2021 ​ 2020 ​ ​ ​ ​ ​ ​ (in thousands) ​ Deferred tax assets: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net operating loss carryforwards ​ ​ ​ ​ $ 315,552 ​ $ 177,899 ​ Intangibles ​ ​ ​ ​ ​ 4,443 ​ ​ — ​ Research and development tax credit carryforwards ​ ​ ​ ​ ​ 38,725 ​ ​ 24,332 ​ Reserves and accruals ​ ​ ​ ​ ​ 14,098 ​ ​ 21,770 ​ Lease Liabilities ​ ​ ​ ​ ​ 16,843 ​ ​ 7,123 ​ Deferred revenue ​ ​ ​ ​ ​ 6,363 ​ ​ 6,386 ​ Stock-based compensation ​ ​ ​ ​ ​ 15,928 ​ ​ 10,673 ​ Total deferred tax assets before valuation allowance ​ ​ ​ ​ ​ 411,952 ​ ​ 248,183 ​ Less: valuation allowance ​ ​ ​ ​ ​ (396,079) ​ ​ (222,521) ​ ​ ​ ​ ​ ​ ​ 15,873 ​ ​ 25,662 ​ Deferred tax liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Convertible debt ​ ​ ​ ​ ​ — ​ ​ (19,143) ​ Right-of-use lease assets ​ ​ ​ ​ ​ (15,873) ​ ​ (6,519) ​ Net deferred tax assets ​ ​ ​ ​ $ — ​ $ — ​
Schedule of reconciliation of the beginning and ending amount of gross unrecognized tax benefits	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 2020 ​ 2019 ​ ​ (in thousands) ​ Balance at beginning of year ​ $ 11,500 ​ $ 8,619 ​ $ 7,362 ​ Additions based on tax positions related to the current year ​ ​ 6,017 ​ ​ 2,889 ​ ​ 1,426 ​ Additions (reductions) for tax positions of prior years ​ ​ (3) ​ ​ (8) ​ ​ (169) ​ Balance at end of year ​ $ 17,514 ​ $ 11,500 ​ $ 8,619 ​

Net Loss per Share (Tables)

Net Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2021
Net Loss per Share
Basic and diluted net loss per share	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ ​ 2021 ​ 2020 ​ 2019 ​ ​ (in thousands, except per share data) Numerator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss used to compute net loss per share, basic and diluted ​ $ (471,716) ​ $ (229,743) ​ $ (124,827) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Denominator: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average number of shares used in computing net loss per share, basic and diluted ​ 90,558 ​ 81,011 ​ 69,555 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Net loss per share, basic and diluted ​ $ (5.21) ​ $ (2.84) ​ $ (1.79) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​
Total outstanding potentially dilutive shares	​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ ​ 2021 2020 2019 ​ (in thousands) ​ Options to purchase common stock ​ 5,898 6,707 8,497 ​ Restricted stock units ​ 3,988 ​ 4,188 ​ 2,404 ​ Employee stock purchase plan ​ 33 ​ 37 ​ 32 ​ Convertible Note ​ 7,411 ​ 7,411 ​ — ​ Estimated earnout shares for an asset acquisition ​ 353 ​ — ​ — ​ ​ ​ 17,683 18,343 ​ 10,933 ​

Description of Business (Detail

Description of Business (Details)	12 Months Ended
	Dec. 31, 2021segmentsubsidiary
Description of Business
Number of operating segments | segment	1
Number of subsidiaries | subsidiary	3

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Liquidity Matters (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended					12 Months Ended
	Jul. 31, 2021	Sep. 30, 2020	Apr. 30, 2020	Oct. 31, 2019	Apr. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Apr. 26, 2019	Dec. 31, 2018
Policies
Net (loss) income						$ (471,716)	$ (229,743)	$ (124,827)
Accumulated deficit						1,394,836	929,318
Cash, cash equivalents and restricted cash						84,614	48,855	$ 61,981		$ 51,004
Marketable securities						829,896	688,606
Short-term Credit Line, outstanding balance						$ 50,052	$ 50,054
Common stock, shares issued	5,175,000	4,791,665		5,714,286	5,263,158	95,140,000	86,223,000
Stock issued (in dollars per share)	$ 113			$ 35	$ 19
Payment of offering expenses	$ 400	$ 300		$ 400	$ 600
Proceeds from issuance of common stock	$ 551,200	$ 271,000		$ 216,200	$ 108,100
Net proceeds							$ 278,316
Loss on debt extinguishment							$ 5,848
Convertible Notes
Policies
Outstanding principal balance			$ 287,500			$ 287,500
Per annum interest rate (as a percent)			2.25%			2.25%
Equity offering
Policies
Common stock, shares issued	5,175,000	4,791,665		6,571,428	6,052,631
Stock issued (in dollars per share)	$ 113	$ 60		$ 35	$ 19
Payment of offering expenses	$ 400	$ 300		$ 400	$ 600
Proceeds from issuance of common stock	$ 551,200	$ 271,000		$ 216,200	$ 108,100
Option for additional shares
Policies
Common stock, shares issued				857,142					789,473

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Asset acquisition (Details) - In-process research and development acquisition $ in Millions	Sep. 10, 2021USD ($)shares
Asset Acquisition [Line Items]
Asset acquisition, consideration transferred	$ 35.6
Issuance of common stock | shares	276,346
Fair value of common stock issued	$ 30.9
Cash consideration	3.9
Net liabilities assumed	0.2
Acquisition related costs	0.6
Value of additional shares potentially issuable	$ 35
Number of additional shares potentially issuable | shares	269,547

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Summary of Significant Accounting Policies
Cash and cash equivalents in balance sheet	$ 84,386	$ 48,668
Restricted cash, current portion in balance sheet	228	187
Total cash, cash equivalents and restricted cash in statements of cash flows	$ 84,614	$ 48,855	$ 61,981	$ 51,004

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Investments (Details) $ in Millions	Dec. 06, 2021USD ($)
Summary of Significant Accounting Policies
Investment in "MyOme" equity securities without readily determinable fair value	$ 4

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Concentration (Details) - customer	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Sales | Customer
Risk and Uncertainties
Number of customers exceeding 10% of benchmark	0	0	0
Accounts receivable | Credit
Risk and Uncertainties
Number of customers exceeding 10% of benchmark	0	0

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Credit Losses (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Summary of Significant Accounting Policies
Beginning balance	$ 4,220
Provision for credit losses	(156)
Write-offs	(1,635)
Total	$ 2,429

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Advertising costs	$ 2.2	$ 0.6	$ 0.2
Capitalized software	$ 2.3	1.7
Impairment of capitalized software			0.1
Capitalized software held for internal use
Estimated useful life (in years)	3 years
Amortized expense	$ 1.1	1	1.2
Shipping and handling costs
Cost of revenues	$ 22	$ 13.3	$ 13.3

Summary of Significant Accou_11

Summary of Significant Accounting Policies - AOCIL (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance	$ 4,259	$ 919
Ending balance	(2,287)	4,259
Net unrealized gain (loss) on available-for-sale securities, net of tax
Accumulated Other Comprehensive Income (Loss) [Line Items]
Increase (decrease) in other comprehensive loss	$ (6,546)	$ 3,340

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Property (Details)	12 Months Ended
	Dec. 31, 2021
Internal-use software
Property and Equipment
Estimated useful life	P3Y
Machinery and equipment | Minimum
Property and Equipment
Estimated useful life	P3Y
Machinery and equipment | Maximum
Property and Equipment
Estimated useful life	P5Y

Summary of Significant Accou_13

Summary of Significant Accounting Policies - Inventory (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Summary of Significant Accounting Policies
Inventory obsolescence charges	$ 0.9	$ 0.2	$ 0.3

Summary of Significant Accou_14

Summary of Significant Accounting Policies - Accounting Pronouncements (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Outstanding principle	$ 287,500
Net carrying amount	280,394
Accumulated deficit	(1,394,836)	$ (929,318)
Convertible Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest expense	7,696
Outstanding principle	287,500
Previously reported
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest expense	$ 9,400
Previously reported | Convertible Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Outstanding principle		287,500
Unamortized debt discount and issuance cost		(85,007)
Net carrying amount		202,493
Additional paid-in-capital		(1,411,286)
Accumulated deficit		(929,318)
Adoption Adjustment | Cumulative effect adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Accumulated deficit		404
Accounting Standards Update 2020-06 | Convertible Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Outstanding principle		287,500
Unamortized debt discount and issuance cost		(8,333)
Net carrying amount		279,167
Additional paid-in-capital		(1,328,410)
Accumulated deficit		(923,120)
Accounting Standards Update 2020-06 | Adoption Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reduction in net loss from continuing operations per share	$ 0.10
Accounting Standards Update 2020-06 | Adoption Adjustment | Convertible Notes
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Unamortized debt discount and issuance cost		76,674
Net carrying amount		76,674
Additional paid-in-capital		82,876
Accumulated deficit		$ 6,198

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		12 Months Ended
	Jul. 31, 2021	Feb. 28, 2019	Mar. 31, 2021	Jun. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	May 31, 2021	Aug. 31, 2019
Deferred revenue, Long-term					$ 21,318	$ 22,805
Other assets					18,820	14,743
Deferred revenue					28,722	72,930
Deferred revenue, current portion					7,404	50,125
Total revenues					625,486	391,005	$ 302,328
Deferred revenue, long-term portion					21,318	22,805
Revenue recognized during the period that was included in deferred revenues at the beginning of the period					37,784
Product
Revenue recognized					5,700	5,400	2,400
Cost of revenues					302,663	185,865	162,604
Total revenues					567,149	367,211	269,881
Licensing and other
Cost of revenues					15,755	17,755	12,866
Total revenues					58,337	$ 23,794	32,447
Genetic testing services and provision of IVD kits
Revenue recognized during the period that was included in deferred revenues at the beginning of the period					300
Qiagen
Proceeds from license agreement								$ 5,000
Agreement term						10 years
Revenue, remaining performance obligation								40,000
Revenue recognized during the period that was included in deferred revenues at the beginning of the period					28,600
Qiagen | Volume, regulatory and commercial milestones
Revenue, remaining performance obligation								$ 10,000
Qiagen | Other licensing and other revenue
Refunds of revenues previously deferred			$ 10,000
Deferred revenue			$ 28,600
BGI Genomics
Proceeds from license agreement		$ 50,000		$ 35,600
Receivable				2,500
Deferred revenue, Long-term					20,400
Deferred revenue, current portion					3,200
Deferred revenue, long-term portion					20,400
BGI Genomics | Sequencing services
Other assets				6,000
BGI Genomics | Sequencing products
Other assets				4,000
BGI Genomics | Sequencing products and services
Other assets				$ 10,000
Foundation Medicine ("FMI")
Proceeds from license agreement							16,300
Agreement term						5 years
Automatic renewals, successive period thereafter						1 year
Deferred revenue, Long-term					900
Deferred revenue, current portion					500
Deferred revenue, long-term portion					900
Foundation Medicine ("FMI") | Milestone payments
Proceeds from license agreement	$ 1,000
Deferred revenue, current portion					$ 2,000				$ 1,000
Foundation Medicine ("FMI") | Upfront licensing fees and prepaid revenues
Initial transaction price										$ 13,300
Foundation Medicine ("FMI") | Developmental, regulatory, and commercial milestones
Initial transaction price										$ 32,000
Foundation Medicine ("FMI") | Developmental performance milestones
Proceeds from license agreement							3,000
Foundation Medicine ("FMI") | Licensing fees and prepaid revenue
Proceeds from license agreement							$ 13,300

Revenue Recognition - Disaggreg

Revenue Recognition - Disaggregation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Total revenues	$ 625,486	$ 391,005	$ 302,328
United States
Disaggregation of Revenue [Line Items]
Total revenues	590,872	365,660	260,846
Americas, excluding U.S.
Disaggregation of Revenue [Line Items]
Total revenues	4,047	3,469	3,218
Europe, Middle East, India, and Africa
Disaggregation of Revenue [Line Items]
Total revenues	20,429	14,332	15,434
Asia Pacific and Other
Disaggregation of Revenue [Line Items]
Total revenues	10,138	7,544	22,830
Insurance carriers
Disaggregation of Revenue [Line Items]
Total revenues	492,563	300,220	210,919
Laboratory partners
Disaggregation of Revenue [Line Items]
Total revenues	100,019	58,196	59,876
Patients
Disaggregation of Revenue [Line Items]
Total revenues	32,904	32,589	31,533
Licensing and other
Disaggregation of Revenue [Line Items]
Total revenues	$ 58,337	$ 23,794	$ 32,447

Revenue Recognition - Accounts

Revenue Recognition - Accounts Receivable and Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Assets
Accounts receivable	$ 122,074	$ 78,565
Liabilities:
Deferred revenue, current portion	7,404	50,125
Deferred revenue, long-term portion	21,318	22,805
Total deferred revenues	$ 28,722	$ 72,930

Revenue Recognition - Changes i

Revenue Recognition - Changes in Balance of Deferred Revenues (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Revenue Recognition
Balance	$ 72,930
Increase in deferred revenues	7,915
Reclasses from deferred revenues to other short-term liabilities	(10,080)
Revenue recognized during the period that was included in deferred revenues at the beginning of the period	(37,784)
Revenue recognized from performance obligations satisfied within the same period	(4,259)
Balance	$ 28,722

Revenue Recognition - Deferred

Revenue Recognition - Deferred Revenues (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Revenue recognized during the period that was included in deferred revenues at the beginning of the period	$ 37,784
Deferred revenue, current portion	7,404	$ 50,125
Deferred revenue, Long-term	21,318	22,805
Deferred revenue	28,722	$ 72,930
BGI Genomics
Deferred revenue, current portion	3,200
Deferred revenue, Long-term	20,400
Foundation Medicine ("FMI")
Deferred revenue, current portion	500
Deferred revenue, Long-term	900
BGI Genomics and Foundation Medicine ("FMI")
Revenue recognized during the period that was included in deferred revenues at the beginning of the period	8,900
Revenue recognized	4,300
Qiagen
Revenue recognized during the period that was included in deferred revenues at the beginning of the period	28,600
Genetic testing services and provision of IVD kits
Revenue recognized during the period that was included in deferred revenues at the beginning of the period	$ 300

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of long-term debt	$ 715,700
Recurring | Available-for-sale securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	839,937	$ 717,596
Recurring | Money market deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	10,041	28,990
Recurring | U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	688,097	597,744
Recurring | Corporate bonds and notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	52,337	12,328
Recurring | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	89,462	78,534
Recurring | Level 1 | Available-for-sale securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	698,138	626,734
Recurring | Level 1 | Money market deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	10,041	28,990
Recurring | Level 1 | U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	688,097	597,744
Recurring | Level 2 | Available-for-sale securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	141,799	90,862
Recurring | Level 2 | Corporate bonds and notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	52,337	12,328
Recurring | Level 2 | Municipal securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total financial assets	$ 89,462	$ 78,534

Financial Instruments (Details)

Financial Instruments (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)position	Dec. 31, 2020USD ($)
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Estimated Fair Value	$ 829,896	$ 688,606
Proceeds from investments sold	$ 187,600	30,100
Number of investments, unrealized loss position | position	61
Unrealized loss position	$ 604,700
Amortized Cost
Less than or equal to one year	274,879
Greater than one year but less than five years	557,304
Total	832,183
Fair Value
Less than or equal to one year	275,331
Greater than or equal to one year but less than five years	554,565
Total	829,896
Available-for-sale securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	842,224	713,337
Gross Unrealized Gain	1,342	4,310
Gross Unrealized Loss	(3,629)	(51)
Estimated Fair Value	839,937	717,596
Money market deposits
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	10,041	28,990
Estimated Fair Value	10,041	28,990
U.S. Treasury securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	689,640	594,252
Gross Unrealized Gain	1,081	3,512
Gross Unrealized Loss	(2,624)	(20)
Estimated Fair Value	688,097	597,744
Corporate bonds and notes
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	52,729	12,331
Gross Unrealized Gain		2
Gross Unrealized Loss	(392)	(5)
Estimated Fair Value	52,337	12,328
Municipal securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Amortized Cost	89,814	77,764
Gross Unrealized Gain	261	796
Gross Unrealized Loss	(613)	(26)
Estimated Fair Value	89,462	78,534
Cash equivalents | Available-for-sale securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Estimated Fair Value	10,041	28,990
Short-term investments | Available-for-sale securities
Debt Securities, Available-for-sale, Fair Value to Amortized Cost [Abstract]
Estimated Fair Value	$ 829,896	$ 688,606

Balance Sheet Components - Allo

Balance Sheet Components - Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Allowance for doubtful accounts
Beginning balance	$ 4,220	$ 2,919	$ 1,788
Cumulative-effect adjustment upon adoption of ASU 2016-13	(1,394,836)	(929,318)
Provision for credit losses	(156)	1,354	1,141
Write-offs	(1,635)	(457)	(10)
Total	$ 2,429	4,220	$ 2,919
Cumulative effect adjustment | Adoption Adjustment
Allowance for doubtful accounts
Cumulative-effect adjustment upon adoption of ASU 2016-13		$ 404

Balance Sheet Components - Prop

Balance Sheet Components - Property and Equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2019	Dec. 31, 2020
Property and Equipment, net
Property and equipment, gross	$ 84,929		$ 83,402
Less: Accumulated depreciation and amortization	(19,413)		(50,054)
Total Property and Equipment, net	65,516		33,348
Depreciation expense	11,300
Assets written off	41,900
Impairment charge	0	$ 1,671
Impairment of leasehold improvements		1,200
Impairment of capitalized software		100
Impairment of right-of-use assets		400
Selling, general and administrative
Property and Equipment, net
Impairment charge		$ 1,700
Machinery and equipment
Property and Equipment, net
Property and equipment, gross	$ 33,722		51,001
Furniture and fixtures
Property and Equipment, net
Property and equipment, gross			1,376
Useful Life	3 years
Computer equipment
Property and Equipment, net
Property and equipment, gross	$ 4,893		2,428
Useful Life	3 years
Capitalized software held for internal use
Property and Equipment, net
Property and equipment, gross	$ 2,395		7,417
Useful Life	3 years
Leasehold improvements
Property and Equipment, net
Property and equipment, gross	$ 13,640		14,810
Construction-in-process
Property and Equipment, net
Property and equipment, gross	$ 30,279		$ 6,370
Minimum | Machinery and equipment
Property and Equipment, net
Useful Life	3 years
Maximum | Machinery and equipment
Property and Equipment, net
Useful Life	5 years

Balance Sheet Components - Accr

Balance Sheet Components - Accrued Compensation (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Components
Accrued paid time off	$ 2,567	$ 2,260
Accrued commissions	15,726	12,686
Accrued bonuses	15,854	9,635
Other accrued compensation	6,794	5,790
Total accrued compensation	$ 40,941	$ 30,371

Balance Sheet Components - Othe

Balance Sheet Components - Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance Sheet Components
Reserves for refunds to insurance carriers	$ 17,210	$ 17,366	$ 9,410
Accrued charges for third-party testing	5,849	5,141
Testing and laboratory materials from suppliers	3,799	2,720
Marketing and corporate affairs	7,853	3,325
Legal, audit and consulting fees	11,758	4,189
Accrued shipping charges	969	1,604
Sales tax payable	2,230	1,723
Accrued third-party service fees	13,442	2,355
Clinical trials, studies, and other development	11,218	2,353
Operating lease liabilities, current portion	5,752	7,300
Fixed asset purchases	1,853	1,691
Other accrued interest	1,078	1,078
Other accrued expenses	10,342	9,562
Total other accrued liabilities	$ 93,353	$ 60,407

Balance Sheet Components - Rese

Balance Sheet Components - Reserve Balance and Activities for Refunds (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Balance Sheet Components
Beginning balance	$ 17,366	$ 9,410
Additional reserves	16,340	19,427
Refunds to carriers	(10,784)	(6,066)
Reserves released to revenue	(5,712)	(5,405)
Ending balance	$ 17,210	$ 17,366

Leases (Details)

Leases (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)ft²leaselocation	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Lessee, Lease, Description [Line Items]
Operating lease liabilities, current portion included in other accrued liabilities	$ 5,752	$ 7,300
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Other Accrued Liability, Current	Other Accrued Liability, Current
Operating lease liabilities, long-term portion	$ 61,036	$ 21,246
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	Operating lease liabilities, long-term portion
Operating lease liabilities	$ 66,788
Noncash investing activities related to right-of-use assets	$ 44,400
Weighted average remaining lease term	4 years 9 months 7 days
Weighted average discount rate (as a percent)	6.40%
Lease expense	$ 10,900	7,800	$ 7,800
Impairment of right-of-use assets			400
Operating lease payments	$ 10,300	$ 9,000	$ 8,600
Minimum
Lessee, Lease, Description [Line Items]
Term of lease	1 year
Maximum
Lessee, Lease, Description [Line Items]
Term of lease	5 years
Austin TX, Long-term Lease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	94,000
Number of office space locations | lease	2
Term of lease	132 months
First Expansion Premises
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	32,500
Second Expansion Premises
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	65,222
Corporate Headquarters Lease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	113,000
Number of office space locations | location	2
Term of lease	84 months
Renewal term of lease	5 years
"First Space" Sublease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	88,000
"Second Space" Sublease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	25,000
Corporate Headquarters Lease Amendment
Lessee, Lease, Description [Line Items]
Renewal term of lease	48 months
Lease expense	$ 9,300
Tukwila, WA Lease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	10,000
Term of lease	62 months
Renewal term of lease	5 years
San Carlos, CA Lease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	25,879
Term of lease	48 months
Noncash investing activities related to right-of-use assets	$ 29,700
Lease expense	$ 1,900
San Carlos, CA Lease | Rentable square feet surrendered in lease amendment
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	25,879
South San Francisco, CA Lease
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	11,395
Term of lease	36 months
Lease expense	$ 900
Laboratory space in Canada
Lessee, Lease, Description [Line Items]
Office space (area) | ft²	7,107
Annual lease payment	$ 200
Term of lease	24 months

Leases - Payments (Details)

Leases - Payments (Details) $ in Thousands	Dec. 31, 2021USD ($)
Leases.
2022	$ 9,980
2023	11,082
2024	12,258
2025	12,494
2026	12,845
2027 and thereafter	27,331
Total	85,990
Less: imputed interest	(19,202)
Operating lease liabilities	$ 66,788

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Thousands	Sep. 28, 2021patent	Jun. 01, 2020patent	May 31, 2021patent	Oct. 31, 2020patent	Sep. 30, 2020patent	Jul. 31, 2020claim	Jun. 30, 2020patent	Mar. 31, 2020patentlawsuit	Jan. 31, 2020patent	Dec. 31, 2021USD ($)
Other commitments
Total | $										$ 137,975
Material suppliers
Other commitments
Total | $										16,040
Application service providers
Other commitments
Total | $										35,279
Earnouts for development with third party
Other commitments
Total | $										35,000
Software development provider
Other commitments
Total | $										4,463
Lease commitments
Other commitments
Total | $										29,683
Other material suppliers
Other commitments
Total | $										$ 17,510
CareDX Patent Case
Other commitments
Number of invalid patents	3
Gain contingency, patents allegedly infringed, number									2
CareDX Patent Case | Patent infringement
Other commitments
Number of patent litigations | lawsuit								2
Loss contingency, patents allegedly infringed, number								3
ArcherDX Patent Case
Other commitments
Gain contingency, patents allegedly infringed, number					5
Ravgen Patent Case
Other commitments
Loss contingency, patents allegedly infringed, number		2
Progenity Patent Case
Other commitments
Gain contingency, patents allegedly infringed, number							6
Genosity Inc. Patent Case
Other commitments
Gain contingency, patents allegedly infringed, number				1
Inivitae Patent Case | Patent infringement
Other commitments
Gain contingency, patents allegedly infringed, number			2
Claims remaining | Progenity Patent Case
Other commitments
Number of patent litigations | claim						3
Claims dropped or dismissed | Progenity Patent Case
Other commitments
Number of patent litigations | claim						3

Stock-Based Compensation (Detai

Stock-Based Compensation (Details)	6 Months Ended				12 Months Ended
	Oct. 31, 2021USD ($)shares	Apr. 30, 2021USD ($)shares	Oct. 31, 2020USD ($)shares	Apr. 30, 2020USD ($)shares	Dec. 31, 2021USD ($)periodshares	Dec. 31, 2020USD ($)shares	Dec. 31, 2019USD ($)	Jun. 30, 2015shares
Stock Based Compensation
Shares granted					2,208,000
2015 Plan
Stock Based Compensation
Shares reserved for issuance								3,451,495
Shares reserved for issuance as a proportion of common stock outstanding (as a percent)					4.00%
2015 Plan | Minimum
Stock Based Compensation
Shares reserved for issuance					3,500,000
Employee stock purchase plan
Stock Based Compensation
Shares reserved for issuance					893,548
Shares available for issuance					2,859,711
Shares reserved for issuance as a proportion of common stock outstanding (as a percent)					1.00%
Price in relation to fair market value of common stock on the date of grant, lower range limit (as a percent)					85.00%
Maximum number of shares a participant may receive during the period (in shares)					5,000
Maximum amount of award or purchase during a calendar year | $					$ 25,000
Maximum offering period, term					27 months
Number of expected offering periods each year | period					2
Offering period, expected term					6 months
Number of Shares Purchased	79,820	106,435	136,288	97,247
Total Proceeds | $	$ 7,465,000	$ 6,085,000	$ 4,052,000	$ 3,062,000
Maximum employee contribution of employee's cash compensation (as a percent)					15.00%
Employee stock purchase plan | Minimum
Stock Based Compensation
Shares reserved for issuance					880,000
Performance-based awards
Stock Based Compensation
Stock-based compensation expense | $					$ 50,300,000	$ 17,200,000
Employee and non-employee stock options
Stock Based Compensation
Stock-based compensation expense | $					$ 115,219,000	$ 50,171,000	$ 28,624,000
Shares available for issuance					4,319,000	3,148,000
Employee and non-employee stock options | 2015 Plan
Stock Based Compensation
Vesting period					4 years
Expiration period					10 years
Stock appreciation rights | 2015 Plan
Stock Based Compensation
Expiration period					10 years
Restricted stock units
Stock Based Compensation
Number of shares vested					2,117
Shares granted					2,208

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Options (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Dec. 31, 2019USD ($)$ / shares
Stock Based Compensation
RSUs granted (in shares)	(2,208,000)
RSUs forfeited/cancelled (in shares)	291,000
Employee and non-employee stock options
Stock Based Compensation
Shares available for grant, beginning balance	3,148,000
Additional shares authorized	3,446,000
Options granted (in shares)	(391,000)
Options forfeited (in shares)	33,000
Shares available for grant, end balance	4,319,000	3,148,000
Number of shares
Outstanding, beginning balance (in shares)	6,707,000
Options granted (in shares)	391,000
Options exercised (in shares)	(1,165,000)
Options forfeited (in shares)	(33,000)
Outstanding, end balance (in shares)	5,900,000	6,707,000
Exercisable (in shares)	4,977,000
Vested and expected to vest (in shares)	5,840,000
Weighted-Average Exercise Price
Outstanding, beginning balance (in dollars per share) | $ / shares	$ 11.19
Granted (in dollars per share) | $ / shares	104.03
Exercised (in dollars per share) | $ / shares	10.14
Forfeited (in dollars per share) | $ / shares	15
Outstanding, end balance (in dollars per share) | $ / shares	17.54	$ 11.19
Exercisable (in dollars per share) | $ / shares	10.65
Vested and expected to vest (in dollars per share) | $ / shares	$ 17.17
Additional disclosures
Weighted average contractual term, options outstanding	5 years 4 months 24 days	6 years 14 days
Exercisable (in years)	4 years 10 months 24 days
Vested and expected to vest (in years)	5 years 4 months 13 days
Aggregate intrinsic value, options outstanding | $	$ 451,505	$ 592,468
Aggregate intrinsic value, options exercisable | $	411,841
Aggregate intrinsic value, vested and expected to vest | $	449,026
Aggregate intrinsic value, options exercised | $	97,000	184,700	$ 70,000
Fair value, options vested | $	$ 46,000	$ 52,500,000	$ 11,000
Weighted-average grant date fair value, options granted | $ / shares	$ 104.03	$ 27.70	$ 8.01
Non-employee stock options
Stock Based Compensation
Options granted (in shares)	(31,553)
Number of shares
Options granted (in shares)	31,553
Additional disclosures
Options unvested (in shares)	730
Restricted stock units
Stock Based Compensation
RSUs granted (in shares)	(2,208)
RSUs forfeited/cancelled (in shares)	291

Stock-Based Compensation - Perf

Stock-Based Compensation - Performance-based Awards (Details) - USD ($) $ in Thousands	3 Months Ended										12 Months Ended
	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs Granted (in shares)											2,208,000
Performance-based awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense											$ 50,300	$ 17,200
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs Granted (in shares)											2,208
Vested (in shares)											2,117
Restricted stock units | Fair Market Value
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs Granted (in shares)	205,000	7,000	279,000	22,000	27,000	21,000	436,000		188,000
Vested (in shares)			10,000	2,000	17,000	21,000	408,000		81,000
Restricted stock units | Monte-Carlo
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
RSUs Granted (in shares)	20,000		125,000	32,000			300,000	50,000		300,000
Vested (in shares)				19,000			289,000	50,000		300,000
Employee and non-employee stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)											391,000
Stock-based compensation expense											$ 115,219	$ 50,171	$ 28,624
Employee and non-employee stock options | Black-Scholes Merton
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)		29,000			10,000		129,000
Options Vested (in shares)					10,000		129,000
Employee and non-employee stock options | Monte-Carlo
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted (in shares)		163,000	150,000				150,000			200,000
Options Vested (in shares)							130,000			200,000

Stock-Based Compensation - Assu

Stock-Based Compensation - Assumptions (Details) - shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Valuation of Stock Option Grants to Employees
Expected volatility, minimum		55.00%
Minimum
Valuation of Stock Option Grants to Employees
Expected term (years)		5 years 3 months
Performance-based awards
Valuation of Stock Option Grants to Employees
Risk free interest rate, minimum	0.80%	0.54%
Risk free interest rate, maximum	1.52%	1.64%
Expected volatility, maximum	60.00%	65.00%
Performance-based awards | Minimum
Valuation of Stock Option Grants to Employees
Expected term (years)	7 years 3 months
Performance-based awards | Maximum
Valuation of Stock Option Grants to Employees
Expected term (years)	10 years	7 years 3 months
Employee and non-employee stock options
Stock Based Compensation
Options granted (in shares)	391,000
Employee stock options
Valuation of Stock Option Grants to Employees
Risk free interest rate, minimum	0.81%	0.31%	1.60%
Risk free interest rate, maximum	1.67%	1.70%	2.60%
Expected dividend yield	0.00%	0.00%	0.00%
Expected volatility, minimum	55.33%	49.94%	42.53%
Expected volatility, maximum	63.30%	61.96%	45.84%
Employee stock options | Minimum
Valuation of Stock Option Grants to Employees
Expected term (years)	5 years 1 month 9 days	5 years 2 months 19 days	5 years 2 months 23 days
Employee stock options | Maximum
Valuation of Stock Option Grants to Employees
Expected term (years)	10 years	10 years	10 years
Non-employee stock options
Stock Based Compensation
Options granted (in shares)	31,553
Options unvested (in shares)	730

Stock-Based Compensation - Rest

Stock-Based Compensation - Restricted Stock Units (Details)	12 Months Ended
	Dec. 31, 2021$ / sharesshares
Shares
Granted (in shares)	2,208,000
Canceled/Forfeited (in shares)	(291,000)
Restricted stock units
Shares
Balance (in shares)	4,188
Granted (in shares)	2,208
Vested (in shares)	(2,117)
Canceled/Forfeited (in shares)	(291)
Balance (in shares)	3,988
Weighted Average Grant Date Fair Value
Balance (in dollars per share) | $ / shares	$ 34.02
Granted (in dollars per share) | $ / shares	106.74
Vested (in dollars per share) | $ / shares	29.46
Canceled/Forfeited (in dollars per share) | $ / shares	55.16
Balance (in dollars per share) | $ / shares	$ 74.33

Stock-Based Compensation - Comp

Stock-Based Compensation - Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Employee and non-employee stock options
Stock based compensation expense
Options granted (in shares)	391,000
Stock-based compensation expense	$ 115,219	$ 50,171	$ 28,624
Unrecognized compensation expense	$ 233,300
Unrecognized compensation expense, weighted average period of recognition	2 years 10 months 24 days
Employee and non-employee stock options | Cost of revenues
Stock based compensation expense
Stock-based compensation expense	$ 4,811	1,691	937
Employee and non-employee stock options | Research and development
Stock based compensation expense
Stock-based compensation expense	25,868	11,424	5,354
Employee and non-employee stock options | Selling, general and administrative
Stock based compensation expense
Stock-based compensation expense	84,540	37,056	22,333
Employee stock options
Stock based compensation expense
Stock-based compensation expense	113,686	49,215	27,989
Employee stock options | Cost of revenues
Stock based compensation expense
Stock-based compensation expense	4,811	1,691	905
Employee stock options | Research and development
Stock based compensation expense
Stock-based compensation expense	24,507	10,777	5,354
Employee stock options | Selling, general and administrative
Stock based compensation expense
Stock-based compensation expense	$ 84,368	36,747	21,730
Non-employee stock options
Stock based compensation expense
Options granted (in shares)	31,553
Options unvested (in shares)	730
Stock-based compensation expense	$ 1,533	956	635
Non-employee stock options | Cost of revenues
Stock based compensation expense
Stock-based compensation expense			32
Non-employee stock options | Research and development
Stock based compensation expense
Stock-based compensation expense	1,361	647
Non-employee stock options | Selling, general and administrative
Stock based compensation expense
Stock-based compensation expense	$ 172	$ 309	$ 603

Debt (Details)

Debt (Details)	1 Months Ended	3 Months Ended	12 Months Ended
	Apr. 30, 2020USD ($)	Dec. 31, 2021USD ($)D$ / sharesshares	Dec. 31, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)D$ / sharesshares	Dec. 31, 2019USD ($)	Jul. 31, 2021$ / sharesshares	Sep. 30, 2020$ / sharesshares	Oct. 31, 2019$ / sharesshares	Apr. 30, 2019$ / sharesshares	Sep. 30, 2015USD ($)
Debt Instrument [Line Items]
Proceeds from Convertible Note, net of issuance costs				$ 278,316,000
Common Stock, Par or Stated Value Per Share | $ / shares		$ 0.0001	$ 0.0001	$ 0.0001
Issuance of common stock to Orbimed					$ 507,000
Common stock, shares issued | shares		95,140,000	95,140,000	86,223,000		5,175,000	4,791,665	5,714,286	5,263,158
Stock issued (in dollars per share) | $ / shares						$ 113		$ 35	$ 19
Stock price (in dollars per share) | $ / shares							$ 60
Carrying value		$ 280,394,000	$ 280,394,000
Debt, repayment amount				$ 79,200,000
Accrued Interest		1,078,000	1,078,000	1,078,000
Amortization of debt discount and issuance cost			1,227,000	149,000	457,000
Interest expense			8,305,000	$ 15,082,000	10,693,000
Convertible Notes
Debt Instrument [Line Items]
Aggregate principal amount	$ 287,500,000	287,500,000	$ 287,500,000
Per annum interest rate (as a percent)	2.25%		2.25%
Interest expense			$ 7,696,000
Debt instrument, term			7 years
Effective interest rate (as a percent)				2.72%
Principal amount per convertible note	$ 1,000	$ 1,000
Threshold business days | D		5
Conversion price (in dollars per share) | $ / shares				$ 38.79
Initial conversion rate				25.7785
Convertible to shares of common stock				7,411,704
Percentage of principal amount converted				100.00%
Convertible Notes | Accounting Standards Update 2020-06
Debt Instrument [Line Items]
Carrying value				$ 279,167,000
Commencing after September 30, 2020 | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D		30
Percentage of conversion price		130.00%
5 consecutive trading day period | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D		5
Percentage of conversion price		98.00%
Redeemable for cash on or after May 2024 | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D				30
Percentage of conversion price				130.00%
Percentage of principal amount converted				100.00%
Level 2
Debt Instrument [Line Items]
Fair value of long-term debt		$ 715,700,000	$ 715,700,000
Minimum | Commencing after September 30, 2020 | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D		20
Minimum | Redeemable for cash on or after May 2024 | Convertible Notes
Debt Instrument [Line Items]
Threshold trading days | D				20
Line Of Credit-UBS
Debt Instrument [Line Items]
Maximum borrowing capacity										$ 50,000,000
Outstanding balance		$ 49,000,000	49,000,000
Interest expense			600,000	$ 800,000	1,700,000
Interest paid			600,000	$ 800,000	$ 1,700,000
Debt, interest accrued			$ 1,100,000
Line Of Credit-UBS | LIBOR
Debt Instrument [Line Items]
Spread on interest rate (as a percent)			1.10%

Debt - Carrying Amount (Details

Debt - Carrying Amount (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2021
Debt
Debt principal balance		$ 287,500
Loss on debt extinguishment	$ 5,848

Debt - Discount and Issuance Co

Debt - Discount and Issuance Costs (Details) - Convertible Notes	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Effective interest rate (as a percent)		2.72%
Debt instrument, term	7 years

Debt - Convertible Notes Balanc

Debt - Convertible Notes Balances (Details) $ in Thousands	Dec. 31, 2021USD ($)
Outstanding principle	$ 287,500
Unamortized debt discount and debt issuance cost	(7,106)
Net carrying amount	280,394
Convertible Notes
Outstanding principle	$ 287,500

Debt - Interest Expense Recogni

Debt - Interest Expense Recognized Related To Convertible Notes (Details) - Convertible Notes $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)
Cash interest expense
Contractual interest expense	$ 6,469
Non-cash interest expense
Amortization of debt discount and debt issuance cost	1,227
Total interest expense	$ 7,696

Stockholders' Equity (Details)

Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 10, 2021	Jul. 31, 2021	Sep. 30, 2020	Oct. 31, 2019	Apr. 30, 2019	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Apr. 26, 2019	Dec. 31, 2018
Stock price (in dollars per share)			$ 60
Stock issued (in dollars per share)		$ 113		$ 35	$ 19
Payment of offering expenses		$ 400	$ 300	$ 400	$ 600
Proceeds from issuance of common stock		$ 551,200	$ 271,000	$ 216,200	$ 108,100
Research and development						$ 264,208	$ 100,035	$ 51,357
Preferred stock, shares authorized						50,000,000
Preferred stock, shares issued						0
Preferred stock, shares outstanding						0
Common stock, shares authorized						750,000,000	750,000,000
Common stock, par value (in dollars per share)						$ 0.0001	$ 0.0001
Common stock, shares issued		5,175,000	4,791,665	5,714,286	5,263,158	95,140,000	86,223,000
Common stock, shares outstanding						95,140,000	86,223,000
In-process research and development acquisition
Asset acquisition, consideration transferred	$ 35,600
Issuance of common stock	276,346
Fair value of common stock issued	$ 30,900
Cash consideration	3,900
Net liabilities assumed	200
Acquisition related costs	600
Value of additional shares potentially issuable	$ 35,000
Number of additional shares potentially issuable	269,547
Option for additional shares
Common stock, shares issued				857,142					789,473
Common stock
Common stock, shares issued						95,140,000	86,223,000	78,005,000		62,083,000

Disposal of Business (Details)

Disposal of Business (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2019	Sep. 30, 2019	Sep. 11, 2019
Gain from disposal of business		$ 14,388
Impairment charge	$ 0	1,671
Impairment of leasehold improvements		1,200
Impairment of capitalized software		100
Impairment of right-of-use asset		400
Exit or disposal activity	400
Termination benefits		100
Early contract termination fee	$ 300
Selling, general and administrative
Impairment charge		1,700
Evercord
Estimated consideration		15,377	$ 15,400
Cash consideration			9,700
Accounts receivable		5,782	1,000
Assets		6,201
Deferred revenues				$ 5,200
Gain from disposal of business		$ 14,388
Contingent consideration | Evercord
Total consideration			$ 4,700

Disposal of Business - Summary

Disposal of Business - Summary of Gain from Disposal (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019
Net gain realized on disposal	$ 14,388
Evercord
Proceeds on disposal:	15,377	$ 15,400
Accounts receivable, net	5,782	$ 1,000
Equipment and inventory	419
Total assets sold	6,201
Deferred revenues	5,212
Net assets and liabilities sold	989
Net gain realized on disposal	$ 14,388

Income Taxes - Effective Tax Ra

Income Taxes - Effective Tax Rates (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Effective tax rates differing from U.S. federal statutory rate
U.S. Federal taxes (benefit) at statutory rate	$ (98,931,000)	$ (48,226,000)	$ (25,794,000)
State tax expense	(29,206,000)	(10,672,000)	(6,607,000)
Research and development credits	(9,193,000)	(3,964,000)	(1,645,000)
Stock-based compensation	(46,128,000)	(23,791,000)	(7,544,000)
Foreign tax	167,000	55,000	1,612,000
Other nondeductible items	344,000	792,000	769,000
Nondeductible officers' compensation	24,387,000	8,984,000	609,000
Acquisition costs	8,901,000
Change in valuation allowance	150,277,000	76,920,000	40,599,000
Provision for income taxes	$ 618,000	$ 98,000	$ 1,999,000
U.S. Federal taxes (benefit) at statutory rate (as a percent)	(21.00%)	(21.00%)	(21.00%)
State tax expense (as a percent)	(6.20%)	(4.65%)	(5.38%)
Research and development credits (as a percent)	(1.95%)	(1.73%)	(1.34%)
Stock-based compensation (as a percent)	(9.80%)	(10.36%)	(6.14%)
Foreign tax differential (as a percent)	0.04%	0.02%	1.31%
Other nondeductible items (as a percent)	0.07%	0.35%	0.63%
Nondeductible officers' compensation (as a percent)	5.18%	3.91%	0.50%
Acquisition costs (as a percent)	1.89%
Change in valuation allowance (as a percent)	31.90%	33.50%	33.05%
Provision for income taxes (as a percent)	0.13%	0.04%	1.63%
Income tax expense	$ 618,000	$ 98,000	$ 1,999,000
Foreign withholding tax expense			1,900,000
Foreign income tax expense			100,000
State income tax expense	300,000	9,000	$ 40,000
Clinical testing and software licensing
Effective tax rates differing from U.S. federal statutory rate
Foreign income tax expense	$ 300,000	$ 100,000

Income Taxes - Deferred Income

Income Taxes - Deferred Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes
Valuation allowance	$ 396,079	$ 222,521
Effect Of Tax Cuts And Jobs Act Of 2017 [Abstract]
Corporate tax rate	21.00%	21.00%	21.00%
Deferred tax assets
Net operating loss carryforwards	$ 315,552	$ 177,899
Intangibles	4,443
Research and development tax credit carryforwards	38,725	24,332
Reserves and accruals	14,098	21,770
Lease Liabilities	16,843	7,123
Deferred revenue	6,363	6,386
Stock based compensation	15,928	10,673
Total deferred tax assets before valuation allowance	411,952	248,183
Less: valuation allowance	(396,079)	(222,521)
Deferred tax assets, net	15,873	25,662
Deferred tax liabilities
Convertible debt		(19,143)
Right-of-use lease assets	(15,873)	(6,519)
Net deferred tax assets

Income Taxes - Net Operating Lo

Income Taxes - Net Operating Loss Carryforwards (Details) $ in Millions	Dec. 31, 2021USD ($)
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 1,300
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	796.7
Foreign
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 4

Income Taxes - Tax Credit Carry

Income Taxes - Tax Credit Carryforwards (Details) $ in Millions	Dec. 31, 2021USD ($)
Tax Credit Carryforward [Line Items]
Taxable income required for full realization of deferred tax assets	$ 1,500
Federal | Research and development tax credit carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	34.5
Federal | Tax credit that can be carried forward indefinitely
Tax Credit Carryforward [Line Items]
Tax credit carryforward	950.2
State | Research and development tax credit carryforward
Tax Credit Carryforward [Line Items]
Tax credit carryforward	$ 23

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Line Items]
Interest and penalties accrued	$ 0
Reconciliation of the beginning and ending amount of gross unrecognized tax benefits
Balance at beginning of year	11,500	$ 8,619	$ 7,362
Additions based on tax positions related to the current year	6,017	2,889	1,426
Additions (reductions) for tax positions of prior years	(3)	(8)	(169)
Balance at end of year	17,514	11,500	8,619
Research and development tax credit carryforward
Income Taxes [Line Items]
Unrecognized tax benefits increase	$ 6,000	$ 2,900	$ 1,300

Net Loss per Share - Loss per S

Net Loss per Share - Loss per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss used to compute net loss per share, basic and diluted	$ (471,716)	$ (229,743)	$ (124,827)
Denominator:
Weighted-average number of shares used in computing net loss per share, basic	90,558	81,011	69,555
Weighted-average number of shares used in computing net loss per share, diluted	90,558	81,011	69,555
Net loss per share, basic (in dollars per share)	$ (5.21)	$ (2.84)	$ (1.79)
Net loss per share, diluted (in dollars per share)	$ (5.21)	$ (2.84)	$ (1.79)
Potentially dilutive shares not included in diluted per share calculation	17,683	18,343	10,933
Convertible Notes
Denominator:
Convertible, If-converted value in excess of principal	$ 441,900
Potentially dilutive shares not included in diluted per share calculation	7,411	7,411

Net Loss per Share - Potentiall

Net Loss per Share - Potentially Dilutive Shares (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares not included in diluted per share calculation	17,683	18,343	10,933
Employee and non-employee stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares not included in diluted per share calculation	5,898	6,707	8,497
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares not included in diluted per share calculation	3,988	4,188	2,404
Employee stock purchase plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares not included in diluted per share calculation	33	37	32
Convertible Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares not included in diluted per share calculation	7,411	7,411
Estimated earnout shares for an asset acquisition
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potentially dilutive shares not included in diluted per share calculation	353