Twist Bioscience (TWST) 10-K 13 Dec 19 2019 FY Annual report Financial data

Cover Page

Cover Page - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Dec. 09, 2019	Mar. 29, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--09-30
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Registrant Name	Twist Bioscience Corp
Entity Central Index Key	0001581280
Entity Shell Company	false
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Security Exchange Name	NASDAQ
Entity Address, State or Province	CA
Title of 12(b) Security	Common Stock
Trading Symbol	TWST
Entity Common Stock, Shares Outstanding		33,118,096
Entity Incorporation, State or Country Code	DE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Public Float			$ 402

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Current assets:
Cash and cash equivalents	$ 46,735	$ 80,757
Short-term investments	91,372
Accounts receivable, net	12,104	5,419
Inventories	7,330	6,028
Prepaid expenses and other current assets	2,594	3,467
Total current assets	160,135	95,671
Property and equipment, net	20,835	12,331
Goodwill	1,138	1,138
Intangible assets, net	508	712
Restricted cash, non-current	579	579
Other non-current assets	3,799	5,360
Total assets	186,994	115,791
Liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)
Redeemable convertible preferred stock		290,483
Current liabilities:
Accounts payable	9,760	7,531
Accrued expenses	5,965	2,166
Accrued compensation	10,479	5,401
Current portion of long-term debt	3,333	2,500
Other current liabilities	817	939
Total current liabilities	30,354	18,537
Redeemable convertible preferred stock warrant liability		631
Long-term debt, net of current portion	4,400	7,218
Other non-current liabilities	158	344
Total liabilities	34,912	26,730
Commitments and contingencies (Note 7)
Stockholders' equity (deficit)
Preferred stock
Common stock
Additional paid-in capital	470,425	9,346
Accumulated other comprehensive income	181	87
Accumulated deficit	(318,524)	(210,855)
Total stockholders' equity (deficit)	152,082	(201,422)
Total liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)	$ 186,994	115,791
Series A Mezzanine Equity [Member]
Liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)
Redeemable convertible preferred stock		9,141
Series B Mezzanine Equity [Member]
Liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)
Redeemable convertible preferred stock		25,900
Series C Mezzanine Equity [Member]
Liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)
Redeemable convertible preferred stock		36,726
Series D Mezzanine Equity [Member]
Liabilities, redeemable convertible preferred stock and stockholders' equity (deficit)
Redeemable convertible preferred stock		$ 218,716

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2019	Sep. 30, 2018
Preferred stock, par value	$ 0.00001	$ 0.00001
Preferred stock, share authorized	10,000,000	0
Preferred stock, share issued	0	0
Preferred stock, share outstanding	0	0
Common stock, par value	$ 0.00001	$ 0.00001
Common stock, share authorized	100,000,000	21,210,000
Common stock, share issued	32,872,675	3,206,048
Common stock, share outstanding	32,872,675	3,206,048
Series A Redeemable Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value	$ 0.00001	$ 0.00001
Redeemable convertible preferred stock, share authorized	0	2,854,576
Redeemable convertible preferred stock, share issued	0	2,817,723
Redeemable convertible preferred stock, share outstanding	0	2,817,723
Series B Redeemable Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value	$ 0.00001	$ 0.00001
Redeemable convertible preferred stock, share authorized	0	3,331,878
Redeemable convertible preferred stock, share issued	0	3,315,645
Redeemable convertible preferred stock, share outstanding		3,315,645
Series C Redeemable Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value	$ 0.00001	$ 0.00001
Redeemable convertible preferred stock, share authorized	0	2,510,354
Redeemable convertible preferred stock, share issued	0	2,491,483
Redeemable convertible preferred stock, share outstanding	0	2,491,483
Series D Redeemable Convertible Preferred Stock [Member]
Redeemable convertible preferred stock, par value	$ 0.00001	$ 0.00001
Redeemable convertible preferred stock, share authorized	0	10,475,252
Redeemable convertible preferred stock, share issued	0	10,326,454
Redeemable convertible preferred stock, share outstanding	0	10,326,454

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Revenues	$ 54,385	$ 25,427	$ 10,767
Operating expenses:
Cost of revenues	47,426	32,189	24,020
Research and development	35,683	20,347	19,169
Selling, general and administrative	80,126	43,450	26,060
Total operating expenses	163,235	95,986	69,249
Loss from operations	(108,850)	(70,559)	(58,482)
Interest income	3,032	999	412
Interest expense	(1,294)	(1,313)	(905)
Other income (expense), net	(265)	(121)	(55)
Loss before income taxes	(107,377)	(70,994)	(59,030)
Provision for income taxes	(292)	(242)	(280)
Net loss attributable to common stockholders	(107,669)	(71,236)	(59,310)
Other comprehensive loss:
Change in unrealized gain (loss) on investments	49		(9)
Foreign currency translation adjustment	45	54	33
Comprehensive loss	$ (107,575)	$ (71,182)	$ (59,286)
Net loss per share attributable to common stockholders—basic and diluted	$ (3.92)	$ (25.51)	$ (24.49)
Weighted average shares used in computing net loss per share attributable to common stockholders—basic and diluted	27,461,844	2,792,743	2,422,243

Consolidated Statements of Rede

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total		Series A Redeemable Convertible Preferred Stock [Member]	Series B Redeemable Convertible Preferred Stock [Member]	Series C Redeemable Convertible Preferred Stock [Member]	Series D Redeemable Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income [Member]	Accumulated deficit [Member]
Beginning Balance at Sep. 30, 2016			$ 9,141	$ 25,900	$ 36,726	$ 62,270
Beginning Balance , shares at Sep. 30, 2016			2,817,723	3,315,645	2,491,483	2,938,714
Issuance of Series D redeemable convertible preferred stock, net of financing costs						$ 65,596
Issuance of Series D redeemable convertible preferred stock, net of financing costs, shares						3,095,375
Ending Balance at Sep. 30, 2017			$ 9,141	$ 25,900	$ 36,726	$ 127,866
Ending Balance , shares at Sep. 30, 2017			2,817,723	3,315,645	2,491,483	6,034,089
Beginning Balance at Sep. 30, 2016	$ (76,611)							$ 3,689	$ 9	$ (80,309)
Beginning Balance , shares at Sep. 30, 2016							3,146,233
Vesting of restricted stock units	4							4
Exercise of stock options	$ 162							162
Exercise of stock options , shares	32,586						32,586
Issuance of common stock warrants	$ 486							486
Stock-based compensation	1,887							1,887
Other comprehensive income	24								24
Net loss	(59,310)	[1]								(59,310)
Ending Balance at Sep. 30, 2017	(133,358)							6,228	33	(139,619)
Ending Balance , shares at Sep. 30, 2017							3,178,819
Issuance of Series D redeemable convertible preferred stock, net of financing costs, shares						4,292,365
Ending Balance at Sep. 30, 2018	290,483		$ 9,141	$ 25,900	$ 36,726	$ 218,716
Ending Balance , shares at Sep. 30, 2018			2,817,723	3,315,645	2,491,483	10,326,454
Issuance of common stock in public offering						$ 90,850
Exercise of stock options	$ 215							215
Exercise of stock options , shares	62,862						62,862
Repurchase of early exercised stock options , shares							(9,639)
Stock-based compensation	$ 2,961							2,961
Forfeiture of restricted common stock , shares							(21,146)
Treasury stock purchase, Shares							(4,848)
Treasury stock purchase	(58)							(58)
Other comprehensive income	54								54
Net loss	(71,236)	[1]								(71,236)
Ending Balance at Sep. 30, 2018	(201,422)							9,346	87	(210,855)
Ending Balance , shares at Sep. 30, 2018							3,206,048
Ending Balance , shares at Sep. 30, 2019			0		0	0
Issuance of common stock in public offering	153,852							153,852
Issuance of common stock in public offering, shares							10,062,500
Vesting of restricted stock units, shares							8,352
Issuance of shares under the employee stock purchase plan	2,700							2,700
Issuance of shares under the employee stock purchase plan, shares							219,144
Exercise of stock options	$ 2,264							2,264
Exercise of stock options , shares	331,205						331,205
Conversion of redeemable convertible preferred stock warrant liability to equity	$ 631							631
Conversion of redeemable convertible preferred stock to common stock	290,462		$ (9,141)	$ (25,900)	$ (36,726)	$ (218,716)		290,462
Conversion of redeemable convertible preferred stock to common stock , shares			(2,817,723)	(3,315,645)	(2,491,483)	(10,326,454)	18,951,305
Repurchase of early exercised stock options , shares							(442)
Stock-based compensation	11,170							11,170
Net exercise of stock warrants , shares							94,563
Other comprehensive income	94								94
Net loss	(107,669)									(107,669)
Ending Balance at Sep. 30, 2019	$ 152,082							$ 470,425	$ 181	$ (318,524)
Ending Balance , shares at Sep. 30, 2019							32,872,675
[1]	Adjusted to reflect the retrospective adoption of Accounting Standards Update (ASU) 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash.

Consolidated Statements of Re_2

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity (Deficit) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Net of underwriting discounts, commissions and offering expenses	$ 17,210
Series D Redeemable Convertible Preferred Stock [Member]
Issuance of redeemable convertible preferred stock, net of financing cost		$ 339	$ 165

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2019	Sep. 30, 2018		Sep. 30, 2017
Cash flows from operating activities
Net loss		$ (107,669)	$ (71,236)	[1]	$ (59,310)	[1]
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation and amortization		6,111	5,727	[1]	5,021	[1]
Loss on disposal of property and equipment		189	55	[1]	507	[1]
Stock-based compensation		11,170	2,961	[1]	1,891	[1]
Discount accretion on investment securities		(1,249)
Non-cash interest expense		233	254	[1]	363	[1]
Change in fair value of redeemable convertible preferred stock warrant liability	[1]		(13)		261
Amortization of debt discount		282	308	[1]	95	[1]
Changes in assets and liabilities:
Accounts receivable, net		(6,685)	(3,073)	[1]	(1,623)	[1]
Inventories		(1,302)	(4,202)	[1]	(599)	[1]
Prepaid expenses and other current assets		746	(1,760)	[1]	(324)	[1]
Other non-current assets		(2,064)	(812)	[1]	(481)	[1]
Accounts payable		3,278	3,759	[1]	560	[1]
Accrued expenses		4,210	(114)	[1]	621	[1]
Accrued Compensation		5,060	1,932	[1]	1,067	[1]
Other liabilities		(247)	50	[1]	650	[1]
Net cash used in operating activities		(87,937)	(66,164)	[1]	(51,301)	[1]
Cash flows from investing activities
Purchases of property and equipment		(14,757)	(3,688)	[1]	(6,594)	[1]
Proceeds from sale of property and equipment		21	17	[1]	266	[1]
Purchases of investments		(177,574)	(3,523)	[1]	(40,587)	[1]
Maturity of investments		87,500	34,500	[1]	36,925	[1]
Net cash provided by (used in) investing activities		(104,810)	27,306	[1]	(9,990)	[1]
Cash flows from financing activities
Proceeds from exercise of stock options		2,170	331	[1]	205	[1]
Proceeds from public offerings, net of underwriting discounts, commissions and offering expenses		156,208
Proceeds from issuance of Series D redeemable convertible preferred stock, net of issuance costs	[1]		90,850		65,596
Proceeds from issuance under employee stock purchase plan		2,700
Payments of deferred offering costs	[1]		(2,359)
Borrowings of long-term debt	[1]				2,174
Repayments of long-term debt		(2,500)			(4,173)	[1]
Net cash provided by financing activities		158,578	88,822	[1]	63,802	[1]
Effect of exchange rates on cash, cash equivalents and restricted cash		30
Net increase (decrease) in cash, cash equivalents and restricted cash		(34,139)	49,964		2,511
Cash, cash equivalents, and restricted cash at beginning of year	[1]	81,537	31,573		29,062
Cash, cash equivalents, and restricted cash at end of year		47,398	81,537	[1]	31,573	[1]
Supplemental disclosure of cash flow information
Interest paid		779	751	[1]	702	[1]
Income taxes paid, net of refunds		291	179	[1]	6	[1]
Non-cash investing and financing activities
Property and equipment additions included in accrued expenses and accounts payable		170	344	[1]	285	[1]
Fair value of warrants issued in connection with debt	[1]				$ 486
Deferred offering costs included in accounts payable and accrued expenses	[1]		$ 1,308
Conversion of redeemable convertible preferred stock warrant liability to equity		631
Conversion of redeemable convertible preferred stock to common stock		$ 290,462
[1]	Adjusted to reflect the retrospective adoption of Accounting Standards Update (ASU) 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash.

The company

The company	12 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company	1. The company Twist Bioscience Corporation (the Company) was incorporated in the state of Delaware on February 4, 2013. The Company is a synthetic biology company that has developed a disruptive DNA synthesis platform. DNA is used in many applications across different industries: industrial chemicals, academic, healthcare and agriculture. The core of our platform is a proprietary technology that pioneers a new method of manufacturing synthetic DNA by “writing” DNA on a silicon chip. We have combined this technology with proprietary software, scalable commercial infrastructure and an e-commerce DNA-based The Company has a limited operating history and its prospects are subject to risks, expenses and uncertainties frequently encountered by companies in this industry. These risks include, but are not limited to, the uncertainty of availability of additional financing, market acceptance of its products, the ability to retain and attract new customers, and the uncertainty of achieving future profitability. The Company has generated net losses in all periods since inception. As of September 30, 2019, the Company had an accumulated deficit of $318.5 million and has not generated positive cash flows from operations since inception. Losses are expected to continue as the Company continues to invest in product development, manufacturing, and sales and marketing. The Company has raised multiple rounds of debt and equity financing since its inception. In October 2018, the Company completed an initial public offering (IPO) of its common stock which raised proceeds of $69.6 million, after deducting underwriting discounts, commissions and offering expenses. In May 2019, the Company completed an underwritten public offering of its common stock with proceeds of $84.3 million, after deducting underwriting discounts and commissions and offering expenses. Management believes that these proceeds combined with existing cash balances on hand will be sufficient to fund operations for at least one year from the issuance of these consolidated financial statements. However, the Company may need to obtain additional financing to fund operations beyond this period, and there can be no assurance that the Company will be successful in raising additional financing on terms which are acceptable to the Company. If the Company requires but is unable to obtain additional funding, the Company could be forced to delay, reduce or eliminate some or all of its research and development programs, product portfolio expansion or commercialization efforts, which could adversely affect its business prospects, or the Company may be unable to continue operations.

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Summary of significant accounting policies	2. Summary of significant accounting policies Basis of presentation and use of estimates The presentation of consolidated financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Such estimates include the valuation of deferred tax assets, stock-based compensation expense, determination of the net realizable value of inventory, and the fair value of the Company’s common stock and redeemable convertible preferred stock warrant liabilities. Actual results could differ from those estimates. The Company’s consolidated financial statements include its wholly-owned subsidiaries. All intercompany balances and accounts are eliminated in consolidation. Risks and uncertainties The Company relies on third parties for the supply and manufacture of its products, including a single-source supplier for a critical component, as well as third-party logistics providers. In instances where these parties fail to perform their obligations, the Company may be unable to find alternative suppliers to satisfactorily deliver its products to its customers on time, if at all. The Company operates in a dynamic and highly competitive industry and believes that changes in any of the following areas could have a material adverse effect on the Company’s future financial position, results of operations, or cash flows : Refer to Note 7 for discussion of our current litigation with Agilent which is set to go to trial in February 2020 and could have a material adverse effect on the Company. The Company has expended and expects to continue to expend substantial funds to complete the research and development of its production process. The Company may require additional funds to commercialize its products and may be unable to entirely fund these efforts with its current financial resources. Additional funds may not be available on acceptable terms, if at all. If adequate funds are unavailable on a timely basis from operations or additional sources of financing, the Company may have to delay the sale of the Company’s products and services which would materially and adversely affect its business, financial condition and operations. Concentration of credit risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents, short-term investments and accounts receivable. Substantially all of the Company’s cash is held by one financial institution that management believes is of high credit quality. Such deposits may, at times, exceed federally insured limits. The Company’s investment policy addresses the level of credit exposure by establishing a minimum allowable credit rating and by limiting the concentration in any one investment. The Company’s accounts receivable is derived from customers located principally in the United States and Europe. The Company maintains credit insurance for certain of its customer balances, performs ongoing credit evaluations of its customers, and maintains allowances for potential credit losses on customers’ accounts when deemed necessary. The Company does not typically require collateral from its customers. Credit losses historically have not been material. The Company continuously monitors customer payments and maintains an allowance for doubtful accounts based on its assessment of various factors including historical experience, age of the receivable balances, and other current economic conditions or other factors that may affect customers’ ability to pay. Customer concentration One customer accounted for more than 10% of total revenues as follows: Year ended September 30, 2019 2018 2017 Customer A 17 % 34 % 40 % One customer accounted for greater than 10% of net accounts receivable as follows: September 30, 2019 2018 Customer A 13 % 27 % Cash and cash equivalents Cash equivalents that are readily convertible to cash are stated at cost, which approximates fair value. The Company considers all highly liquid investments with an original or remaining maturity of three months or less at the time of purchase to be cash equivalents. Cash equivalents consist of investments in money market funds as of September 30, 2019 and 2018. Short-term investments The Company invests in various types of securities, including United States government, commercial paper, and corporate debt securities. It classifies its investments as available-for-sale income equity ( ) Accounts receivable Trade receivables include amounts billed and currently due from customers, recorded at the net invoice value and are not interest bearing. The amounts due are stated at their net estimated realizable value. The Company maintains an allowance for doubtful accounts to provide for the estimated amounts of receivables that will not be collected. The allowance is based upon an assessment of customer creditworthiness, historical payment experience, the age of outstanding receivables and collateral to the extent applicable. The Company re-evaluates The Company has a short order-to-invoice Fair value of financial instruments The carrying amounts of the Company’s financial instruments including cash equivalents, short term investments, and accounts receivable approximate fair value due to their relatively short maturities. The carrying amounts of the redeemable convertible preferred stock warrant liability represent their fair values. Based on the borrowings rates currently available to the Company for loans with similar terms, the carrying value of the Company’s long-term debt approximates its fair value (level 2 within the fair value hierarchy). Inventories Inventory is stated at the lower of cost or net realizable value. Cost is determined using the first-in, first-out Property and equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets or the remaining lease term of the respective leasehold improvements assets, if any. The Company recorded depreciation and amortization expense of $6.1 million, $5.5 million and $4.8 million for the years September 30, 2019, 2018 and 2017, respectively. Estimated lives of property and equipment are as follows: Laboratory equipment 5 Years Furniture, fixtures and other equipment 5 Years Computer equipment 3 Years Computer software 3 Year s Leasehold improvements Lesser of useful life or Maintenance and repairs are charged to expense as incurred. Betterments are capitalized and depreciated through the life of the lease. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the balance sheet and any resulting gain or loss is reflected in operations in the period realized. Capitalized software development costs Costs associated with internal-use to improve e-commerce Capitalized software development costs were $2.3 million and $1.9 million as of September 30, 2019 and 2018, respectively. Capitalized costs are amortized from the project completion date, using the straight-line method over an estimated useful life of the assets, which is three Long-lived assets The Company reviews property and equipment and intangibles for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future undiscounted cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds their fair value Leases The Company has entered into lease agreements for its manufacturing, research and development and office facilities. These leases qualify as and are accounted for as operating leases. Rent expense is recognized on a straight-line basis over the term of the lease and, accordingly, the Company records the difference between cash rent payments and the recognition of rent expense as a prepaid rent asset or a deferred rent liability, as appropriate for each lease. Goodwill and purchased intangible assets Goodwill is evaluated for impairment annually or more frequently if events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. If, based on a qualitative assessment, the Company determines it is more likely than not that goodwill is impaired, a quantitative assessment is performed to determine if the fair value of the Company’s sole reporting unit is less than its carrying value. Purchased intangible assets with finite lives are generally amortized over their estimated useful lives using the straight-line method. The Company reviews intangible assets for impairment whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. Impairment assessments inherently involve judgment as to assumptions about expected future cash flows and the impact of market conditions on those assumptions. Segment information The Company has one business activity, which is manufacturing of synthetic DNA using its semiconductor-based silicon platform and operates as one reportable and operating segment. The Company’s chief operating decision-maker, its Chief Executive Officer (CEO), reviews the Company’s operating results on an aggregate basis for purposes of allocating resources and evaluating financial performance. Revenue recognition Effective October 1, 2017, the Company elected to early adopt the requirements of Accounting Standards Codification (ASC) 606, Revenue from Contracts with Customers The Company’s revenue is generated through the sale of synthetic biology tools, such as synthetic genes, or clonal genes and fragments, oligonucleotides pools, or oligo pools, next generation sequencing, or NGS tools and DNA libraries. The Company accounts for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. Contracts with customers are generally in the written form of a purchase order or a quotation, which outline the promised goods and the agreed upon price. Such orders are often accompanied by a Master Supply or Distribution Agreement that establishes the terms and conditions, rights of the parties, delivery terms, and pricing. The Company assesses collectability based on a number of factors, including past transaction history and creditworthiness of the customer. For all of the Company’s contracts to date, the customer orders a specified quantity of synthetic DNA ; The transaction price is determined based on the agreed upon rates in the purchase order or master supply agreements applied to the quantity of synthetic DNA that was manufactured and shipped to the customer. The Company’s contracts include only one performance obligation – the delivery of the product to the customer. Accordingly, all of the transaction price, net of any discounts, is allocated to the one performance obligation. Therefore, upon delivery of the product, there are no remaining performance obligations. The Company’s shipping and handling activities are considered a fulfillment cost. The Company has elected to exclude all sales and value added taxes from the measurement of the transaction price. The Company has not adjusted the transaction price for significant financing since the time period between the transfer of goods and payment is less than one year. The Company recognizes revenue at a point in time when control of the products is transferred to the customer. Management applies judgment in evaluating when a customer obtains control of the promised good which is generally when the product is shipped or delivered to the customer. The Company’s customer contracts generally include a standard assurance warranty to guarantee that its products comply with agreed specifications. The Company reduces revenue by the amount of expected returns which have been insignificant. The Company has elected the practical expedient to not disclose the consideration allocated to remaining performance obligations and an explanation of when those amounts are expected to be recognized as revenue since the duration of the contracts is less than one year. Refer to Note 15 for the disaggregation of revenues by geography, by product and by industry. The Company does not have any contract assets or contract liabilities as of September 30, 2019 and 2018. For all periods presented, the Company did not recognize revenue from amounts that were included in the contract liability balance at the beginning of each period. In addition, for all periods presented, there was no revenue recognized in a reporting period from performance obligations satisfied in previous periods. Based on the nature of the Company’s contracts with customers which are recognized over a term of less than 12 months, the Company has elected to use the practical expedient whereby costs to obtain a contract are expensed as they are incurred. Research and development Research and development expenses consist of compensation costs, employee benefits, subcontractors, research supplies, allocated facility related expenses and allocated depreciation and amortization. All research and development costs are expensed as incurred. Advertising costs Costs related to advertising and promotions are expensed to sales and marketing as incurred. Advertising and promotion expenses for the years ended September 30, 2019, 2018 and 2017, were $1.3 million, $0.9 million and $0.1 million, respectively. Government contract payments The Company recognizes payments received from its funded research and development agreement with the Defense Advanced Research Projects Agency (DARPA), when milestones are achieved and records them as a reduction of research and development expenses. In fiscal 2019 and 2018, the Company received $0.5 million and $0.3 million, respectively, in DARPA payments. There were no DARPA payments received during the year ended September 30, 2017. Redeemable convertible preferred stock warrant liability Outstanding warrants that were related to the Company’s redeemable convertible preferred stock are classified as liabilities on the balance sheet. As the warrants to purchase redeemable convertible preferred stock were exercisable into shares of convertible preferred stock, the Company had recognized a liability for the fair value of its warrants on the consolidated balance sheets upon issuance and subsequently remeasured the liability to fair value at the end of each reporting period. In connection with the closing of our Common stock warrants Warrants to purchase the Company’s common stock issued in conjunction with debt are recorded as additional paid-in-capital paid-in-capital Stock-based compensation The Company maintains performance incentive plans under which incentive and nonqualified stock options and restricted stock units are granted primarily to employees and may be granted to members of the board of directors and certain non-employee The Company recognizes stock compensation in accordance with ASC 718, Compensation—Stock Compensation The Company recognizes fair value of stock options granted to non-employees Net loss per share attributable to common stockholders The Company calculates its basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method are re-allocated to Basic and diluted net loss per share of common stock attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase, and excludes any dilutive effects of employee stock-based awards and warrants. Because the Company has reported a net loss for the years ended September 30, 2019, 2018 and 2017, diluted net loss per common share is the same as the basic net loss per share for those years. The Company considered all series of its convertible preferred stock to be participating securities as they were entitled to receive noncumulative dividends prior and in preference to any dividends on shares of common stock. Due to the Company’s net losses, there was no impact on the loss per share calculation in applying the two-class method Reverse stock split In October 2018, the Company’s stockholders approved a one-for-0.101 Income taxes The Company accounts for income taxes using the asset and liability method whereby deferred tax asset and liability accounts are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that are currently in effect. Valuation allowances are established where necessary to reduce deferred tax assets to the amounts expected to be realized. Deferred offering costs Deferred offering costs, which consist of direct incremental legal, consulting, banking and accounting fees relating to the Company’s IPO, were initially capitalized and subsequently offset against proceeds from the IPO within stockholders’ equity. As of September 30, 2019, there were no capitalized deferred offering costs on the consolidated balance sheets. As of September 30, 2018, there was $3.7 million of deferred offering costs within other non-current Recent accounting pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (Topic 606) In February 2016, the FASB issued new lease accounting guidance in ASU 2016-02, Leases right-of-use The Company estimates the key change upon adoption of the standard will result in balance sheet recognition of additional lease assets and lease liabilities as of October 1, 2019, which wi ll be which the Company expects to be consistent with the future minimum lease payments disclosed in Note 7 In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments and held-to-maturity debt for available-for-sale debt 20 In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments zero-coupon of ASU 2016-15 did In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash beginning-of-period end-of-period non-current September 30, 2019 2018 2017 Cash and cash equivalents 46,735 80,757 31,227 Restricted cash, non-current 579 579 202 Restricted cash, current (within prepaid expenses and other current assets) 84 201 144 Total cash, cash equivalents and restricted cash 47,398 81,537 31,573 Amounts included in restricted cash primarily related to security deposits and a letter of credit with a financial institution, both in connection with office space lease agreements. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805) Clarifying the Definition of a Business In January 2017, the FASB issued ASU 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. In May 2017, the FASB issued ASU 2017-09, Compensation Stock Compensation (Topic 718): Scope of Modification Accounting 2017-09, of ASU 2017-09 did In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Subtopic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement 2018-13

Fair value measurement

Fair value measurement	12 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair value measurement	3. Fair value measurement The Company assesses the fair value of financial instruments based on the provisions of ASC 820, Fair Value Measurements Level 1 Level 2 Level 3 In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. The following table sets forth the cash and cash equivalents, and short-term investments as of September 30, 2019: (in thousands) Amortized Gross Gross Fair Cash and cash equivalents $ 46,735 $ — $ — $ 46,735 Short-term investments 91,323 49 — 91,372 Total $ 138,058 $ 49 $ — $ 138,107 The following table sets forth the cash and cash equivalents as of September 30, 2018: (in thousands) Amortized Gross Gross Fair Cash and cash equivalents $ 80,757 $ — $ — $ 80,757 Total $ 80,757 $ — $ — $ 80,757 As of September 30, 2019, financial assets and liabilities measured and recognized at fair value are as follows: (in thousands) Level 1 Level 2 Level 3 Fair value Assets Cash and cash equivalents $ 19,344 $ — $ — $ 19,344 Money market funds 27,390 — — 27,390 Corporate bonds — 8,530 — 8,530 Commercial paper — 28,361 — 28,361 U.S. government treasury bills 54,482 — — 54,482 Total $ 101,216 $ 36,891 $ — $ 138,107 As of September 30, 2018, financial assets and liabilities measured and recognized at fair value are as follows: (in thousands) Level 1 Level 2 Level 3 Fair value Assets Cash and cash equivalents $ 46,823 $ — $ — $ 46,823 Money market funds 33,934 — — 33,934 Total $ 80,757 $ — $ — $ 80,757 Liabilities Redeemable convertible preferred stock warrant liability $ — $ — $ 631 $ 631 The Company did not have short–term investments at September 30, 2018. Redeemable convertible preferred stock warrants The following table provides a reconciliation of beginning and ending balances of the Level 3 instruments during the years ended September 30, 2017, 2018 and 2019: (in thousands) Series A Series B Series C Series D Total Redeemable convertible preferred stock warrant liability: Fair value as of September 30, 2016 $ 184 $ 57 $ 108 $ 34 $ 383 Change in fair value recorded in other income (expense), net 147 53 44 17 261 Fair value as of September 30, 2017 $ 331 $ 110 $ 152 $ 51 $ 644 Change in fair value recorded in other income (expense), net 34 (16 ) (22 ) (9 ) (13 ) Fair value as of September 30, 2018 $ 365 $ 94 $ 130 $ 42 $ 631 Conversion of redeemable convertible preferred stock warrants to common stock warrants (365 ) (94 ) (130 ) (42 ) (631 ) Fair value as of September 30, 2019 $ — $ — $ — $ — $ —

Balance sheet components

Balance sheet components	12 Months Ended
	Sep. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Balance sheet components	4. Balance sheet components The Company’s accounts receivable, net balance consists of the following: September 30, (in thousands) 2019 2018 Trade Receivables $ 11,085 $ 5,439 Other Receivables 1,313 75 Allowance for Doubtful Accounts (294 ) (95 ) Accounts Receivable, net $ 12,104 $ 5,419 Inventories consist of the following: September 30, (in thousands) 2019 2018 Raw Materials $ 4,900 $ 2,988 Work-in-process 1,157 2,273 Finished Goods 1,273 767 $ 7,330 $ 6,028 Property and Equipment, net consists of the following: September 30, (in thousands) 2019 2018 Laboratory equipment $ 26,021 $ 18,865 Furniture, fixtures and other equipment 1,760 613 Computer equipment 2,777 2,137 Computer software 3,507 3,094 Leasehold improvements 3,772 3,340 Construction in progress 5,991 1,534 43,828 29,583 Less: Accumulated depreciation and amortization (22,993 ) (17,252 ) $ 20,835 $ 12,331

Goodwill and intangible assets

Goodwill and intangible assets	12 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and intangible assets	5. Goodwill and intangible assets There were no changes to the carrying value of goodwill during the years ended September 30, 2019 and 2018. Total amortization expense related to intangible assets was $0.2 million for the year ended September 30, 2019, $0.2 million for the year ended September 30, 2018 and $0.2 million for the year ended September 30, 2017. The intangible assets balances are presented below: September 30, 2019 (in thousands, except for years) Useful lives Gross Accumulated Net book Developed Technology 6 $ 1,220 $ (712 ) $ 508 Tradenames & Trademarks 2 20 (20 ) — Total indefinite-lived intangible assets $ 1,240 $ (732 ) $ 508 September 30, 2018 (in thousands, except for years) Useful lives Gross Accumulated Net book Developed Technology 6 $ 1,220 $ (508 ) $ 712 Tradenames & Trademarks 2 20 (20 ) — Total indefinite-lived intangible assets $ 1,240 $ (528 ) $ 712 Future annual amortization expense is as follows (in thousands): Years ending September 30, 2020 203 2021 203 202 2 102 $ 508

Long-term debt

Long-term debt	12 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Long-term debt	6. Long-term debt In September 2017, the Company entered into a Fourth Amended and Restated Loan and Security Agreement (the Fourth Loan) with SVB for loan amounts aggregating up to $20.0 million in a series of three advances. The first advance provides a principal amount of $10.0 million, the second advance provides a principal amount of $5.0 million and the third advance provides a principal amount of $5.0 million during their respective draw down periods. The draw down periods for the second and third advances under this agreement have expired as of January 31, 2018 and June 30, 2018, respectively and were not utilized. In connection with the first advance the Company issued a warrant to purchase 64,127 shares of common stock at an exercise price of $6.24 per share. The Fourth Loan contains a subjective acceleration clause under which the Fourth Loan could become due and payable to SVB in the event of a material adverse change in the Company’s business. The term of the loan was 51 months with an interest rate of prime plus 3.00% and a final payment fee of $0.7 million. The first advance, totaling $10.0 million, was drawn in September 2017 and comprised $7.8 million to refinance a prior loan and a new advance of $2.2 million. The debt provides for interest only payments through December 31, 2018 at which time monthly principal payments become due. In addition, the Company obtained a revolving loan facility for a principal amount of up to $10.0 million for which the principal amount outstanding under the revolving line would accrue interest at a floating per annum rate equal to one percentage point (1.00%) above the prime rate, which interest shall be payable monthly. The Company accounted for this transaction as a debt modification and did not incur any gain or loss relating to the modification. The Company’s credit facilities contain customary representations and warranties and customary affirmative and negative covenants applicable to the Company and its subsidiaries, including, among other things, restrictions on changes in business, management, ownership or business locations, indebtedness, encumbrances, investments, mergers or acquisitions, dispositions, maintenance of collateral accounts, prepayment of other indebtedness, distributions and transactions with affiliates. The credit facilities contain customary events of default subject in certain cases to grace periods and notice requirements, including (a) failure to pay principal, interest and other obligations when due, (b) material misrepresentations, (c) breach of covenants, conditions or agreements in the credit facilities, (d) default under material indebtedness, (e) certain bankruptcy events, (f) a material adverse change; (g) attachment, levy or restraint on business, (h) default with respect to subordinated debt, (i) cross default under the Company’s credit facilities, and (j) government approvals being revoked. As of September 30, 2017, all rights, title and interest to the Company’s personal property with the exception of the Company’s intellectual property, have been pledged as collateral, including cash and cash equivalents, short-term investments, accounts receivable, contractual rights to payment, license agreements, general intangibles, inventory and equipment. The Company was in compliance with all covenants under the loan and security agreement with SVB as of September 30, 2019 and 2018. Future maturities of the Fourth Loan as of September 30, 2019 are as follows: (in thousands) Principal Interest Total Years ending September 30, 2020 $ 3,333 486 $ 3,819 2021 3,333 214 3,547 2022 834 11 845 7,500 711 8,211 Less: Interest (711 ) Total amount of loan principal 7,500 Less unamortized debt discount (269 ) Add: accretion of final payment fee 502 $ 7,733

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	7. Commitments and contingencies Litigation In February 2016, a complaint was filed in the Superior Court of the State of California (County of Santa Clara), dated February 3, 2016 on behalf of Agilent Technologies, Inc. (Agilent), against the Company and its CEO, Dr. Emily Leproust (the Complaint) alleging (i) breach of contract against the CEO, and two current or former employees (ii) breach of duty of loyalty against the CEO, and (iii) misappropriation of trade secrets by the Company, the CEO, and two current or former employees. On December 7, 2018, the Court granted Agilent’s motion to amend its complaint, permitting Agilent to file its Second Amended Complaint. This new complaint adds amended allegations against the Company and the CEO, and also new claims for breach of contract and trade secret misappropriation against two individuals: a current Company employee and a former Company employee. The Court also set trial to begin on February 24, 2020. The Company believes that the complaint is without merit, and intends to continue vigorously defending itself. The Company is currently unable to predict the ultimate outcome of this matter or estimate a reasonably possible loss or range of loss, and no amounts have been accrued in the consolidated financial statements. Indemnifications In the ordinary course of business, the Company enters into agreements that may include indemnification provisions. Pursuant to such agreements, the Company may indemnify, hold harmless and defend the indemnified parties for losses suffered or incurred by the indemnified party. Some of the provisions will limit losses to those arising from third-party actions. In some cases, the indemnification will continue after the termination of the agreement. The maximum potential amount of future payments the Company could be required to make under these provisions is not determinable. To date, the Company has not incurred material costs to defend lawsuits or settle claims related to these indemnification provisions. The Company has also entered into indemnification agreements with its directors and officers that may require it to indemnify its directors and officers against liabilities that may arise by reason of their status or service as directors or officers to the fullest extent permitted by corporate law. The Company also has directors’ and officers’ insurance. Leases The Company leases certain of its facilities under non-cancellable Future minimum lease payments under all non-cancelable (in thousands) Operating Years ending September 30 : 2020 $ 6,671 2021 5,909 2022 5,979 2023 6,064 2024 6,029 Thereafter 10,067 Total minimum lease payments $ 40,719 Rent expense was $4.9 million, $2.5 million and $2.2 million for the years ended September 30, 2019, 2018 and 2017, respectively. Rent expense is measured based upon amortizing minimum lease payments, including rent escalations under the lease term, using the straight-line method over the term of the lease. Prepaid rent was $1.6 million as of September 30, 2019. There was no no

Related party transactions

Related party transactions	12 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Related party transactions	8. Related party transactions During the year ended September 30, 2019, the Company purchased raw materials from a related party investor in the amount of $3.2 million. Payable balances and cash receipts and receivable balances with the related party were immaterial as of September 30, 2019. During the year ended September 30, 2018, the Company purchased raw materials from a related party investor in the amount of $2.3 million. Payable balances and cash receipts and receivable balances with the related party were immaterial as of September 30, 2018. During the year ended September 30, 2017, the Company sold 170,085 shares of Series D redeemable convertible preferred stock to a related party. The Company also purchased raw materials from a related party investor in the amount of $2.0 million. Payable balances and cash receipts and receivable balances with the related party were immaterial as of September 30, 2017.

Income taxes

Income taxes	12 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income taxes	9. Income taxes The Company recorded provision for income taxes of $0.3 million for the year ended September 30, 2019, $0.2 million for the year ended September 30, 2018 and $0.3 million for the year ended September 30, 2017. The significant components of the Company’s deferred tax assets and liabilities are as follows: September 30, (in thousands) 2019 2018 Net operating loss carryforwards $ 73,341 $ 49,801 Research and development credit carryforwards 6,831 4,621 Other 4,553 1,919 Gross deferred tax assets 84,725 56,341 Less: Valuation allowance (84,598 ) (56,158 ) Net deferred tax assets 127 183 Fixed assets (1 ) (1 ) Intangible assets (126 ) (182 ) Gross deferred tax liabilities (127 ) (183 ) Total net deferred tax asset $ — $ — The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate: Year ended 2019 2018 2017 Tax expense computed at the federal statutory rate 21 % 24 % 35 % Change in valuation allowance (22 )% 4 % (35 )% Research and development credit benefit 1 % 1 % 1 % Change in federal tax rate — (28 )% — Other expenses — (1 )% (1 )% Total income tax expense — % — % — % Based on the available objective evidence, management believes it is more likely than not that the deferred tax assets will not be fully realizable. Accordingly, the Company has provided a full valuation allowance against its deferred tax assets at September 30, 2019 and As of September 30, 2019, the Company had net operating loss carryforwards of approximately $293.6 million and $183.4 million available to reduce future taxable income, if any, for federal and state income tax purposes, respectively. The Company also had federal and state research and development credit carryforwards of approximately $5.7 million and $5.1 million, respectively, at September 30, 2019. The federal credits will expire starting in 2033 The provisions of ASC 740-10, Accounting for Uncertainty in Income Taxes The aggregate changes in the balance of gross unrecognized tax benefits are as follows: (in thousands) Federal Balance as of September 30, 2016 822 Increases related to tax positions taken during 2017 562 Increases related to tax positions in prior years 241 Balance as of September 30, 2017 1,625 Increases related to tax positions taken during 2018 624 Balance as of September 30, 2018 $ 2,249 Increases related to tax positions taken during 2019 1,042 Balance as of September 30, 2019 $ 3,291 The Company does not expect a material change in unrecognized tax benefits in the next twelve months. As of September 30, 2019, no unrecognized tax benefit would, if recognized, impact the Company’s effective income tax rate. It is the Company’s policy to include penalties and interest expense related to income taxes as a component of other expense and interest expense, respectively, as necessary. The Company’s management determined that no accrual for interest and penalties was required as of September 30, 2019 and 2018. The Company’s tax years from 2014 through 2018 will remain open for examination by the federal and state authorities for three and four years, respectively, from the date of utilization of any net operating loss or tax credits. The Company currently has no federal or state tax examinations in progress. On December 22, 2017, the Tax Cuts and Jobs Act of 2017, or the Tax Act, was enacted into law making significant changes to the Internal Revenue Code. Changes include, but are not limited to, a federal corporate tax rate decrease from 35% to 21% for tax years beginning after December 31, 2017, the transition of U.S. international taxation from a worldwide tax system to a territorial system, and a one-time

Warrants

Warrants	12 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Warrants	10. Warrants In connection with its long-term debt agreements, the Company issued warrants for its redeemable convertible preferred stock and common stock as follows: Number of (in thousands, except share and per share data) September 30, 2019 Issuance date Expiration date Exercise Warrant class/series: Common stock warrants 18,854 December 22, 2015 December 22, 2025 $ 14.85 Common stock warrants 7,531 March 28, 2016 March 28, 2026 $ 21.24 Total common stock warrants 26,385 Number of Fair (in thousands, except share and per share data) September 30, 2018 Issuance date Expiration date Exercise Warrant class/series: Series A 36,838 $ 365 October 8, 2013 October 8, 2023 $ 3.26 Series B 16,221 94 September 2, 2014 September 2, 2024 $ 7.84 Series C 18,854 130 December 22, 2015 December 22, 2025 $ 14.85 Series D 7,531 42 March 28, 2016 March 28, 2026 $ 21.24 Total preferred stock warrants 79,444 $ 631 Common stock warrants 64,127 $ 486 September 6, 2017 September 6, 2027 $ 6.24 In October 2018, each warrant to purchase redeemable convertible preferred stock was converted to a warrant to purchase common stock immediately prior to the completion of the IPO. In November 2018, a total of 68,901 warrants were net exercised; 36,838 warrants with an exercise price of $3.26 per common share and 32,063 warrants with an exercise price of $6.24 per common share. The transactions were a cashless exercise for a net 57,122 common shares issued by the Company. In July 2019, a total of 32,064 warrants with an exercise price of $6.24 per common share were net exercised for a net 25,422 common shares issued by the Company. In September 2019, a total of 16,221 7.84 12,019

Redeemable convertible preferre

Redeemable convertible preferred stock	12 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Redeemable convertible preferred stock	11. Redeemable convertible preferred stock In October 2018, each share of Series A, Series B, Series C, and Series D redeemable convertible preferred stock was converted into common stock immediately prior to the completion of the IPO.

Common stock

Common stock	12 Months Ended
	Sep. 30, 2019
Equity [Abstract]
Common stock	12. Common stock The fair value of the shares of common stock underlying the Company’s stock options has historically been determined by management and approved by the board of directors. Prior to the Company’s IPO, management and the board of directors determined the fair value of the common stock at the time of grant of any options by considering a number of objective and subjective factors, including valuations performed by an independent third-party specialists, valuations of comparable companies, operating and financial performance, the lack of liquidity of the common stock, recent private stock sale transactions and general and industry-specific economic outlooks. Valuations performed by third-party valuation specialists were completed and used the methodologies, approaches, and assumptions consistent with the AICPA, Accounting and Valuation Guide: Valuation of Privately-Held-Company Equity Securities Issued as Compensation As of September 30, 2019, the Company reserved sufficient shares of common stock for issuance upon conversion of preferred stock and exercise of stock options and warrants. Each share of common stock is entitled to one vote. The holders of shares of common stock are also entitled to receive dividends whenever funds are legally available and when declared by the board of directors, subject to prior rights of the holders of preferred stock.

Stock option plan

Stock option plan	12 Months Ended
	Sep. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock option plan	13. Stock option plan 2018 Equity Incentive Plan On September 26, 2018, the board of directors adopted the 2018 Equity Incentive Plan (the 2018 Plan) as a successor to the 2013 Stock Plan. The maximum aggregate number of shares that may be issued under the 2018 Plan is 5,856,505 shares of the Company’s common stock. The number of shares reserved for issuance under the 2018 Plan will be increased automatically on the first day of each fiscal year, following the fiscal year in which the 2018 Plan became effective, by a number equal to the least of 999,900 shares, 4% of the shares of common stock outstanding at that time, or such number of shares determined by the Company’s board of directors. The common shares issuable under the 2018 Plan were registered pursuant to a registration statement on Form S-8 Any shares subject to outstanding awards under the 2013 Stock Plan that are canceled or repurchased subsequent to the 2018 Plan’s effective date are returned to the pool of shares reserved for issuance under the 2018 Plan. Awards granted under the 2018 Plan may be nonstatutory stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, and performance units. 2018 Employee Stock Purchase Plan On September 26, 2018, the board of directors adopted the 2018 Employee Stock Purchase Plan (the 2018 ESPP). A total of 275,225 shares of the Company’s common stock have been reserved for issuance under the 2018 ESPP. The number of shares reserved for issuance under the 2018 ESPP will be increased automatically on the first day of each fiscal year, following the fiscal year in which the 2018 ESPP becomes effective, by a number equal to the least of 249,470 shares, 1% of the shares of common stock outstanding at that time, or such number of shares determined by the Company’s board of directors. Subject to any plan limitations, the 2018 ESPP allows eligible service providers (through qualified and non-qualified S-8 Unless otherwise determined by the board of directors, the Company’s common stock will be purchased for the accounts of employees participating in the 2018 ESPP at a price per share that is the lesser of 85% of the fair market value of the Company’s common stock on the first trading day of the offering period, which for the initial offering period is the price at which shares of the Company’s common stock were first sold to the public, or 85% of the fair market value of the Company’s common stock on the last trading day of the offering period. During the year ended September 30, 2019, activity under the 2018 ESPP was immaterial. Activity under the equity incentive plans during the years ended September 30, 2019, 2018 and 2017 is summarized below: Shares Options Weighted Weighted (years) Aggregate Outstanding at September 30, 2016 470,623 1,033,612 $ 4.93 8.81 $ 1,343,301 Additional shares authorized 1,035,414 — — Stock options granted (857,082 ) 857,082 8.61 Stock options exercised — (32,586 ) 5.54 Stock options forfeited 38,384 (38,384 ) 5.54 Outstanding at September 30, 2017 687,339 1,819,724 $ 6.63 9.14 $ 7,147,115 Additional shares authorized 905,786 — — Stock options granted (951,310 ) 951,310 10.96 Stock options exercised — (62,862 ) 5.37 Stock options forfeited 187,687 (187,687 ) 7.73 Early exercised options repurchased 9,639 — Forfeiture of restricted common stock 21,146 — — Outstanding at September 30, 2018 860,287 2,520,485 $ 8.22 8.38 $ 11,482,909 Additional shares authorized 2,494,700 — — Stock options granted (1,685,625 ) 1,685,625 25.53 Stock options exercised — (331,205 ) 6.67 Stock options forfeited 324,460 (324,460 ) 14.75 Restricted stock units granted (500,132 ) — — Early exercised options repurchased 442 — — Forfeiture of restricted stock units 26,743 — — Outstanding at September 30, 2019 1,520,875 3,550,445 $ 15.99 8.25 $ 31,997,934 Vested or expected to vest at September 30, 2019 3,550,445 $ 15.99 8.25 $ 31,997,934 Vested and exercisable at September 30, 2019 1,243,634 $ 7.77 7.01 $ 20,125,913 As of September 30, 2019, there was $ 24.8 non-vested Restricted Stock Units Restricted stock primarily consists of restricted stock unit awards (RSUs) which have been granted to employees. The value of an RSU award is based on the Company’s stock price on the date of grant. The shares underlying the RSU awards are not issued until the RSUs vest. Upon vesting, each RSU converts into one share of the Company’s common stock. Activity with respect to the Company’s restricted stock units during the year ended September 30, 2019 was as follows: (in thousands, except share and per share data) Number Weighted Weighted Aggregate Outstanding at September 30, 2018 — $ — — $ — Restricted stock units granted 500,132 26.12 3.87 13,059,488 Restricted stock units vested (11,019 ) 24.69 — — Restricted stock units forfeited (26,743 ) 25.92 — — Outstanding at September 30, 2019 462,370 26.16 3.91 8,959,223 Expected to vest at September 30, 2019 462,370 $ 26.16 3.91 $ 8,959,223 As of September 30, 2019, there was $10.2 million of total unrecognized compensation cost related to these issuances that is expected to be recognized over a weighted average period of 3.99 years. Stock-based compensation Total stock-based compensation expense recognized was as follows: Year ended (in thousands) 2019 2018 2017 Cost of revenues $ 1,345 $ 376 $ 202 Research and development 2,378 705 575 Selling, general and administrative 7,447 1,880 1,114 Total stock-based compensation $ 11,170 $ 2,961 $ 1,891 The Company uses the Black-Scholes option pricing model to calculate the grant date fair value of a stock option. The Black-Scholes model requires various assumptions, including the fair value of the Company’s common stock, expected term, expected dividend yield and expected volatility. The expected volatility of the Company’s stock options is estimated from the historical volatility of selected public companies with comparable characteristics to it, including similarity in size and lines of business. The expected term of stock options represents the period that the Company’s stock-options are expected to be outstanding before being exercised. The risk-free interest rate is based on the implied yield currently available on U.S. treasury notes with terms approximately equal to the expected life of the option. The expected dividend rate is zero as the Company currently has no history or expectation of declaring cash dividends on the Company’s common stock. The fair value of options granted during the years ended September 30, 2019, 2018 and 2017, respectively, were calculated using the weighted average assumptions set forth below: Year ended 2019 2018 2017 Expected term (years) 6.41 6.25 6.25 Expected volatility 60.2 % 66.3 % 65.5 % Risk-free interest rate 2.72 % 2.65 % 2.02 % Dividend yield 0 % 0 % 0 % Weighted average grant date fair value of options granted during the years ended September 30, 2019, 2018 and 2017 was $15.06, $7.08 and $6.63, respectively. Shares subject to repurchase The Company has a right of repurchase with respect to unvested shares issued upon early exercise of options at an amount equal to the original exercise price of each unvested share being repurchased. The Company’s right to repurchase these shares lapses pursuant to the vesting schedule of the original grant, which is generally 25% on the first anniversary of the original grant and ratably on a monthly basis over the remaining 36 months. As of September 30, 2019, 38,157 shares remain subject to the Company’s right of repurchase.

Net loss per share attributable

Net loss per share attributable to common stockholders	12 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Net loss per share attributable to common stockholders	14. Net loss per share attributable to common stockholders The following table sets forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders: Year ended September 30, (in thousands, except share and per share data) 2019 2018 2017 Numerator: Net loss attributable to common stockholders $ (107,669 ) $ (71,236 ) $ (59,310 ) Denominator: Weighted-average shares used in computing net loss per share, basic and diluted 27,461,844 2,792,743 2,422,243 Net loss per share attributable to common stockholders, basic and diluted $ (3.92 ) $ (25.51 ) $ (24.49 ) The potentially dilutive common shares that were excluded from the calculation of diluted net loss per share because their effect would have been antidilutive for the periods presented are as follows: Year ended September 30, 2019 2018 2017 Shares subject to options to purchase common stock 3,550,445 2,520,485 1,819,724 Unvested restricted shares of common stock 23,861 96,750 513,766 Unvested restricted stock units 462,370 — — Unvested shares of common stock issued upon early exercise of stock options 38,157 74,142 44,698 Shares subject to employee stock purchase plan 76,335 — — Shares subject to warrants to purchase common stock 26,385 64,127 64,127 Shares subject to warrants to purchase redeemable convertible preferred stock — 79,444 79,444 Shares of redeemable convertible preferred stock — 18,951,305 14,658,940 Total 4,177,553 21,786,253 17,180,699

Geographic, product and industr

Geographic, product and industry information	12 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Geographic, product and industry information	15. Geographic, product and industry information The table below sets forth revenues by geographic region, based on ship-to Year ended (in thousands) 2019 2018 2017 United States $ 35,936 $ 17,662 $ 8,243 EMEA 14,692 6,557 2,023 APAC 2,761 1,001 274 North America 996 207 227 Total $ 54,385 $ 25,427 $ 10,767 The table below sets forth revenues by products. Year ended (in thousands) 2019 2018 2017 Synthetic genes $ 26,712 $ 17,986 $ 8,122 Oligo pools 4,594 3,002 2,056 DNA libraries 2,036 1,771 517 NGS tools 21,043 2,668 72 Total $ 54,385 $ 25,427 $ 10,767 Revenues by industry were as follows: Year ended September 30, (in thousands) 201 9 2018 2017 Industrial chemicals $ 21,927 $ 14,912 $ 6,702 Academic research 13,835 5,813 2,709 Healthcare 17,424 4,212 1,226 Agricultural 1,199 490 130 Total revenues $ 54,385 $ 25,427 $ 10,767 Long-lived assets located in the United States are $19.8 million and $11.9 million as of September 30, 2019 and 2018. Long-lived assets located outside of the United States were $1.0 million and $0.4 million as of September 30, 2019 and 2018.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Basis of presentation and use of estimates	Basis of presentation and use of estimates The presentation of consolidated financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Such estimates include the valuation of deferred tax assets, stock-based compensation expense, determination of the net realizable value of inventory, and the fair value of the Company’s common stock and redeemable convertible preferred stock warrant liabilities. Actual results could differ from those estimates. The Company’s consolidated financial statements include its wholly-owned subsidiaries. All intercompany balances and accounts are eliminated in consolidation.
Risks and uncertainties	Risks and uncertainties The Company relies on third parties for the supply and manufacture of its products, including a single-source supplier for a critical component, as well as third-party logistics providers. In instances where these parties fail to perform their obligations, the Company may be unable to find alternative suppliers to satisfactorily deliver its products to its customers on time, if at all. The Company operates in a dynamic and highly competitive industry and believes that changes in any of the following areas could have a material adverse effect on the Company’s future financial position, results of operations, or cash flows : Refer to Note 7 for discussion of our current litigation with Agilent which is set to go to trial in February 2020 and could have a material adverse effect on the Company. The Company has expended and expects to continue to expend substantial funds to complete the research and development of its production process. The Company may require additional funds to commercialize its products and may be unable to entirely fund these efforts with its current financial resources. Additional funds may not be available on acceptable terms, if at all. If adequate funds are unavailable on a timely basis from operations or additional sources of financing, the Company may have to delay the sale of the Company’s products and services which would materially and adversely affect its business, financial condition and operations.
Concentration of credit risk	Concentration of credit risk Financial instruments that potentially subject the Company to a concentration of credit risk consist of cash and cash equivalents, short-term investments and accounts receivable. Substantially all of the Company’s cash is held by one financial institution that management believes is of high credit quality. Such deposits may, at times, exceed federally insured limits. The Company’s investment policy addresses the level of credit exposure by establishing a minimum allowable credit rating and by limiting the concentration in any one investment. The Company’s accounts receivable is derived from customers located principally in the United States and Europe. The Company maintains credit insurance for certain of its customer balances, performs ongoing credit evaluations of its customers, and maintains allowances for potential credit losses on customers’ accounts when deemed necessary. The Company does not typically require collateral from its customers. Credit losses historically have not been material. The Company continuously monitors customer payments and maintains an allowance for doubtful accounts based on its assessment of various factors including historical experience, age of the receivable balances, and other current economic conditions or other factors that may affect customers’ ability to pay.
Customer concentration	Customer concentration One customer accounted for more than 10% of total revenues as follows: Year ended September 30, 2019 2018 2017 Customer A 17 % 34 % 40 % One customer accounted for greater than 10% of net accounts receivable as follows: September 30, 2019 2018 Customer A 13 % 27 %
Cash and cash equivalents	Cash and cash equivalents Cash equivalents that are readily convertible to cash are stated at cost, which approximates fair value. The Company considers all highly liquid investments with an original or remaining maturity of three months or less at the time of purchase to be cash equivalents. Cash equivalents consist of investments in money market funds as of September 30, 2019 and 2018.
Short-term investments	Short-term investments The Company invests in various types of securities, including United States government, commercial paper, and corporate debt securities. It classifies its investments as available-for-sale income equity ( )
Accounts receivable	Accounts receivable Trade receivables include amounts billed and currently due from customers, recorded at the net invoice value and are not interest bearing. The amounts due are stated at their net estimated realizable value. The Company maintains an allowance for doubtful accounts to provide for the estimated amounts of receivables that will not be collected. The allowance is based upon an assessment of customer creditworthiness, historical payment experience, the age of outstanding receivables and collateral to the extent applicable. The Company re-evaluates The Company has a short order-to-invoice
Fair value of financial instruments	Fair value of financial instruments The carrying amounts of the Company’s financial instruments including cash equivalents, short term investments, and accounts receivable approximate fair value due to their relatively short maturities. The carrying amounts of the redeemable convertible preferred stock warrant liability represent their fair values. Based on the borrowings rates currently available to the Company for loans with similar terms, the carrying value of the Company’s long-term debt approximates its fair value (level 2 within the fair value hierarchy).
Inventories	Inventories Inventory is stated at the lower of cost or net realizable value. Cost is determined using the first-in, first-out
Property and equipment	Property and equipment Property and equipment are stated at cost less accumulated depreciation and amortization. Depreciation and amortization are computed using the straight-line method over the estimated useful lives of the assets or the remaining lease term of the respective leasehold improvements assets, if any. The Company recorded depreciation and amortization expense of $6.1 million, $5.5 million and $4.8 million for the years September 30, 2019, 2018 and 2017, respectively. Estimated lives of property and equipment are as follows: Laboratory equipment 5 Years Furniture, fixtures and other equipment 5 Years Computer equipment 3 Years Computer software 3 Year s Leasehold improvements Lesser of useful life or Maintenance and repairs are charged to expense as incurred. Betterments are capitalized and depreciated through the life of the lease. When assets are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the balance sheet and any resulting gain or loss is reflected in operations in the period realized.
Capitalized software development costs	Capitalized software development costs Costs associated with internal-use to improve e-commerce Capitalized software development costs were $2.3 million and $1.9 million as of September 30, 2019 and 2018, respectively. Capitalized costs are amortized from the project completion date, using the straight-line method over an estimated useful life of the assets, which is three
Long-lived assets	Long-lived assets The Company reviews property and equipment and intangibles for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability is measured by comparison of the carrying amount to the future undiscounted cash flows which the assets are expected to generate. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds their fair value
Leases	Leases The Company has entered into lease agreements for its manufacturing, research and development and office facilities. These leases qualify as and are accounted for as operating leases. Rent expense is recognized on a straight-line basis over the term of the lease and, accordingly, the Company records the difference between cash rent payments and the recognition of rent expense as a prepaid rent asset or a deferred rent liability, as appropriate for each lease.
Goodwill and purchased intangible assets	Goodwill and purchased intangible assets Goodwill is evaluated for impairment annually or more frequently if events or changes in circumstances indicate that the carrying value of the asset may not be recoverable. If, based on a qualitative assessment, the Company determines it is more likely than not that goodwill is impaired, a quantitative assessment is performed to determine if the fair value of the Company’s sole reporting unit is less than its carrying value. Purchased intangible assets with finite lives are generally amortized over their estimated useful lives using the straight-line method. The Company reviews intangible assets for impairment whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. Impairment assessments inherently involve judgment as to assumptions about expected future cash flows and the impact of market conditions on those assumptions.
Segment information	Segment information The Company has one business activity, which is manufacturing of synthetic DNA using its semiconductor-based silicon platform and operates as one reportable and operating segment. The Company’s chief operating decision-maker, its Chief Executive Officer (CEO), reviews the Company’s operating results on an aggregate basis for purposes of allocating resources and evaluating financial performance.
Revenue recognition	Revenue recognition Effective October 1, 2017, the Company elected to early adopt the requirements of Accounting Standards Codification (ASC) 606, Revenue from Contracts with Customers The Company’s revenue is generated through the sale of synthetic biology tools, such as synthetic genes, or clonal genes and fragments, oligonucleotides pools, or oligo pools, next generation sequencing, or NGS tools and DNA libraries. The Company accounts for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance and collectability of consideration is probable. Contracts with customers are generally in the written form of a purchase order or a quotation, which outline the promised goods and the agreed upon price. Such orders are often accompanied by a Master Supply or Distribution Agreement that establishes the terms and conditions, rights of the parties, delivery terms, and pricing. The Company assesses collectability based on a number of factors, including past transaction history and creditworthiness of the customer. For all of the Company’s contracts to date, the customer orders a specified quantity of synthetic DNA ; The transaction price is determined based on the agreed upon rates in the purchase order or master supply agreements applied to the quantity of synthetic DNA that was manufactured and shipped to the customer. The Company’s contracts include only one performance obligation – the delivery of the product to the customer. Accordingly, all of the transaction price, net of any discounts, is allocated to the one performance obligation. Therefore, upon delivery of the product, there are no remaining performance obligations. The Company’s shipping and handling activities are considered a fulfillment cost. The Company has elected to exclude all sales and value added taxes from the measurement of the transaction price. The Company has not adjusted the transaction price for significant financing since the time period between the transfer of goods and payment is less than one year. The Company recognizes revenue at a point in time when control of the products is transferred to the customer. Management applies judgment in evaluating when a customer obtains control of the promised good which is generally when the product is shipped or delivered to the customer. The Company’s customer contracts generally include a standard assurance warranty to guarantee that its products comply with agreed specifications. The Company reduces revenue by the amount of expected returns which have been insignificant. The Company has elected the practical expedient to not disclose the consideration allocated to remaining performance obligations and an explanation of when those amounts are expected to be recognized as revenue since the duration of the contracts is less than one year. Refer to Note 15 for the disaggregation of revenues by geography, by product and by industry. The Company does not have any contract assets or contract liabilities as of September 30, 2019 and 2018. For all periods presented, the Company did not recognize revenue from amounts that were included in the contract liability balance at the beginning of each period. In addition, for all periods presented, there was no revenue recognized in a reporting period from performance obligations satisfied in previous periods. Based on the nature of the Company’s contracts with customers which are recognized over a term of less than 12 months, the Company has elected to use the practical expedient whereby costs to obtain a contract are expensed as they are incurred.
Research and development	Research and development Research and development expenses consist of compensation costs, employee benefits, subcontractors, research supplies, allocated facility related expenses and allocated depreciation and amortization. All research and development costs are expensed as incurred.
Advertising costs	Advertising costs Costs related to advertising and promotions are expensed to sales and marketing as incurred. Advertising and promotion expenses for the years ended September 30, 2019, 2018 and 2017, were $1.3 million, $0.9 million and $0.1 million, respectively.
Government contract payments	Government contract payments The Company recognizes payments received from its funded research and development agreement with the Defense Advanced Research Projects Agency (DARPA), when milestones are achieved and records them as a reduction of research and development expenses. In fiscal 2019 and 2018, the Company received $0.5 million and $0.3 million, respectively, in DARPA payments. There were no DARPA payments received during the year ended September 30, 2017.
Redeemable convertible preferred stock warrant liability	Redeemable convertible preferred stock warrant liability Outstanding warrants that were related to the Company’s redeemable convertible preferred stock are classified as liabilities on the balance sheet. As the warrants to purchase redeemable convertible preferred stock were exercisable into shares of convertible preferred stock, the Company had recognized a liability for the fair value of its warrants on the consolidated balance sheets upon issuance and subsequently remeasured the liability to fair value at the end of each reporting period. In connection with the closing of our
Common stock warrants	Common stock warrants Warrants to purchase the Company’s common stock issued in conjunction with debt are recorded as additional paid-in-capital paid-in-capital
Stock-based compensation	Stock-based compensation The Company maintains performance incentive plans under which incentive and nonqualified stock options and restricted stock units are granted primarily to employees and may be granted to members of the board of directors and certain non-employee The Company recognizes stock compensation in accordance with ASC 718, Compensation—Stock Compensation The Company recognizes fair value of stock options granted to non-employees Net loss per share attributable to common stockholders The Company calculates its basic and diluted net loss per share attributable to common stockholders in conformity with the two-class method are re-allocated to Basic and diluted net loss per share of common stock attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding during the period, less shares subject to repurchase, and excludes any dilutive effects of employee stock-based awards and warrants. Because the Company has reported a net loss for the years ended September 30, 2019, 2018 and 2017, diluted net loss per common share is the same as the basic net loss per share for those years. The Company considered all series of its convertible preferred stock to be participating securities as they were entitled to receive noncumulative dividends prior and in preference to any dividends on shares of common stock. Due to the Company’s net losses, there was no impact on the loss per share calculation in applying the two-class method
Reverse stock split	Reverse stock split In October 2018, the Company’s stockholders approved a one-for-0.101
Income taxes	Income taxes The Company accounts for income taxes using the asset and liability method whereby deferred tax asset and liability accounts are determined based on differences between financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that are currently in effect. Valuation allowances are established where necessary to reduce deferred tax assets to the amounts expected to be realized.
Deferred offering costs	Deferred offering costs Deferred offering costs, which consist of direct incremental legal, consulting, banking and accounting fees relating to the Company’s IPO, were initially capitalized and subsequently offset against proceeds from the IPO within stockholders’ equity. As of September 30, 2019, there were no capitalized deferred offering costs on the consolidated balance sheets. As of September 30, 2018, there was $3.7 million of deferred offering costs within other non-current
Recent accounting pronouncements	Recent accounting pronouncements In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2014-09, Revenue from Contracts with Customers (Topic 606) In February 2016, the FASB issued new lease accounting guidance in ASU 2016-02, Leases right-of-use The Company estimates the key change upon adoption of the standard will result in balance sheet recognition of additional lease assets and lease liabilities as of October 1, 2019, which wi ll be which the Company expects to be consistent with the future minimum lease payments disclosed in Note 7 In June 2016, the FASB issued ASU 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments and held-to-maturity debt for available-for-sale debt 20 In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments zero-coupon of ASU 2016-15 did In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash beginning-of-period end-of-period non-current September 30, 2019 2018 2017 Cash and cash equivalents 46,735 80,757 31,227 Restricted cash, non-current 579 579 202 Restricted cash, current (within prepaid expenses and other current assets) 84 201 144 Total cash, cash equivalents and restricted cash 47,398 81,537 31,573 Amounts included in restricted cash primarily related to security deposits and a letter of credit with a financial institution, both in connection with office space lease agreements. In January 2017, the FASB issued ASU 2017-01, Business Combinations (Topic 805) Clarifying the Definition of a Business In January 2017, the FASB issued ASU 2017-04, Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment. In May 2017, the FASB issued ASU 2017-09, Compensation Stock Compensation (Topic 718): Scope of Modification Accounting 2017-09, of ASU 2017-09 did In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Subtopic 820): Disclosure Framework—Changes to the Disclosure Requirements for Fair Value Measurement 2018-13

Summary of significant accoun_3

Summary of significant accounting policies (Tables)	12 Months Ended
	Sep. 30, 2019
Schedule Of Estimated Lives of Property And Equipment	Estimated lives of property and equipment are as follows: Laboratory equipment 5 Years Furniture, fixtures and other equipment 5 Years Computer equipment 3 Years Computer software 3 Year s Leasehold improvements Lesser of useful life or
Summary of Cash, Cash Equivalents and Restricted Cash	September 30, 2019 2018 2017 Cash and cash equivalents 46,735 80,757 31,227 Restricted cash, non-current 579 579 202 Restricted cash, current (within prepaid expenses and other current assets) 84 201 144 Total cash, cash equivalents and restricted cash 47,398 81,537 31,573
Sales Revenue, Net [Member]
Schedule of concentration of risk	One customer accounted for more than 10% of total revenues as follows: Year ended September 30, 2019 2018 2017 Customer A 17 % 34 % 40 %
Accounts Receivable [Member]
Schedule of concentration of risk	One customer accounted for greater than 10% of net accounts receivable as follows: September 30, 2019 2018 Customer A 13 % 27 %

Fair value measurement (Tables)

Fair value measurement (Tables)	12 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Cash And Cash Equivalents And Available For Sale Securities At Fair Value	The following table sets forth the cash and cash equivalents, and short-term investments as of September 30, 2019: (in thousands) Amortized Gross Gross Fair Cash and cash equivalents $ 46,735 $ — $ — $ 46,735 Short-term investments 91,323 49 — 91,372 Total $ 138,058 $ 49 $ — $ 138,107 The following table sets forth the cash and cash equivalents as of September 30, 2018: (in thousands) Amortized Gross Gross Fair Cash and cash equivalents $ 80,757 $ — $ — $ 80,757 Total $ 80,757 $ — $ — $ 80,757
Summary of Company's Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	As of September 30, 2019, financial assets and liabilities measured and recognized at fair value are as follows: (in thousands) Level 1 Level 2 Level 3 Fair value Assets Cash and cash equivalents $ 19,344 $ — $ — $ 19,344 Money market funds 27,390 — — 27,390 Corporate bonds — 8,530 — 8,530 Commercial paper — 28,361 — 28,361 U.S. government treasury bills 54,482 — — 54,482 Total $ 101,216 $ 36,891 $ — $ 138,107 As of September 30, 2018, financial assets and liabilities measured and recognized at fair value are as follows: (in thousands) Level 1 Level 2 Level 3 Fair value Assets Cash and cash equivalents $ 46,823 $ — $ — $ 46,823 Money market funds 33,934 — — 33,934 Total $ 80,757 $ — $ — $ 80,757 Liabilities Redeemable convertible preferred stock warrant liability $ — $ — $ 631 $ 631
Summary of Reconciliation of Beginning and Ending Balances of the Level 3 Instruments	The following table provides a reconciliation of beginning and ending balances of the Level 3 instruments during the years ended September 30, 2017, 2018 and 2019: (in thousands) Series A Series B Series C Series D Total Redeemable convertible preferred stock warrant liability: Fair value as of September 30, 2016 $ 184 $ 57 $ 108 $ 34 $ 383 Change in fair value recorded in other income (expense), net 147 53 44 17 261 Fair value as of September 30, 2017 $ 331 $ 110 $ 152 $ 51 $ 644 Change in fair value recorded in other income (expense), net 34 (16 ) (22 ) (9 ) (13 ) Fair value as of September 30, 2018 $ 365 $ 94 $ 130 $ 42 $ 631 Conversion of redeemable convertible preferred stock warrants to common stock warrants (365 ) (94 ) (130 ) (42 ) (631 ) Fair value as of September 30, 2019 $ — $ — $ — $ — $ —

Balance sheet components (Table

Balance sheet components (Tables)	12 Months Ended
	Sep. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Schedule Of Accounts Notes Loans And Financing Receivable	The Company’s accounts receivable, net balance consists of the following: September 30, (in thousands) 2019 2018 Trade Receivables $ 11,085 $ 5,439 Other Receivables 1,313 75 Allowance for Doubtful Accounts (294 ) (95 ) Accounts Receivable, net $ 12,104 $ 5,419
Summary of Inventory	Inventories consist of the following: September 30, (in thousands) 2019 2018 Raw Materials $ 4,900 $ 2,988 Work-in-process 1,157 2,273 Finished Goods 1,273 767 $ 7,330 $ 6,028
Schedule Of Property Plant And Equipment	Property and Equipment, net consists of the following: September 30, (in thousands) 2019 2018 Laboratory equipment $ 26,021 $ 18,865 Furniture, fixtures and other equipment 1,760 613 Computer equipment 2,777 2,137 Computer software 3,507 3,094 Leasehold improvements 3,772 3,340 Construction in progress 5,991 1,534 43,828 29,583 Less: Accumulated depreciation and amortization (22,993 ) (17,252 ) $ 20,835 $ 12,331

Goodwill and intangible assets

Goodwill and intangible assets (Tables)	12 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets Balances	The intangible assets balances are presented below: September 30, 2019 (in thousands, except for years) Useful lives Gross Accumulated Net book Developed Technology 6 $ 1,220 $ (712 ) $ 508 Tradenames & Trademarks 2 20 (20 ) — Total indefinite-lived intangible assets $ 1,240 $ (732 ) $ 508 September 30, 2018 (in thousands, except for years) Useful lives Gross Accumulated Net book Developed Technology 6 $ 1,220 $ (508 ) $ 712 Tradenames & Trademarks 2 20 (20 ) — Total indefinite-lived intangible assets $ 1,240 $ (528 ) $ 712
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	Future annual amortization expense is as follows (in thousands): Years ending September 30, 2020 203 2021 203 202 2 102 $ 508

Long-term debt (Tables)

Long-term debt (Tables)	12 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule Of Maturities Of Long Term Debt	Future maturities of the Fourth Loan as of September 30, 2019 are as follows: (in thousands) Principal Interest Total Years ending September 30, 2020 $ 3,333 486 $ 3,819 2021 3,333 214 3,547 2022 834 11 845 7,500 711 8,211 Less: Interest (711 ) Total amount of loan principal 7,500 Less unamortized debt discount (269 ) Add: accretion of final payment fee 502 $ 7,733

Commitments and contingencies (

Commitments and contingencies (Tables)	12 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Rental Payments for Operating Leases	Future minimum lease payments under all non-cancelable (in thousands) Operating Years ending September 30 : 2020 $ 6,671 2021 5,909 2022 5,979 2023 6,064 2024 6,029 Thereafter 10,067 Total minimum lease payments $ 40,719

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Schedule of Deferred Tax Assets and Liabilities	The significant components of the Company’s deferred tax assets and liabilities are as follows: September 30, (in thousands) 2019 2018 Net operating loss carryforwards $ 73,341 $ 49,801 Research and development credit carryforwards 6,831 4,621 Other 4,553 1,919 Gross deferred tax assets 84,725 56,341 Less: Valuation allowance (84,598 ) (56,158 ) Net deferred tax assets 127 183 Fixed assets (1 ) (1 ) Intangible assets (126 ) (182 ) Gross deferred tax liabilities (127 ) (183 ) Total net deferred tax asset $ — $ —
Schedule of Effective Income Tax Rate Reconciliation	The following is a reconciliation of the statutory federal income tax rate to the Company’s effective tax rate: Year ended 2019 2018 2017 Tax expense computed at the federal statutory rate 21 % 24 % 35 % Change in valuation allowance (22 )% 4 % (35 )% Research and development credit benefit 1 % 1 % 1 % Change in federal tax rate — (28 )% — Other expenses — (1 )% (1 )% Total income tax expense — % — % — %
Schedule of Unrecognized Tax Benefits Roll Forward	The aggregate changes in the balance of gross unrecognized tax benefits are as follows: (in thousands) Federal Balance as of September 30, 2016 822 Increases related to tax positions taken during 2017 562 Increases related to tax positions in prior years 241 Balance as of September 30, 2017 1,625 Increases related to tax positions taken during 2018 624 Balance as of September 30, 2018 $ 2,249 Increases related to tax positions taken during 2019 1,042 Balance as of September 30, 2019 $ 3,291

Warrants (Tables)

Warrants (Tables)	12 Months Ended
	Sep. 30, 2019
Text Block [Abstract]
Summary of Issued Warrants for Its Redeemable Convertible Preferred Stock and Common Stock	In connection with its long-term debt agreements, the Company issued warrants for its redeemable convertible preferred stock and common stock as follows: (in thousands, except share and per share data) Number of Warrant class/series: September 30, 2019 Issuance date Expiration date Exercise Common stock warrants 18,854 December 22, 2015 December 22, 2025 $ 14.85 Common stock warrants 7,531 March 28, 2016 March 28, 2026 $ 21.24 Total common stock warrants 26,385 (in thousands, except share and per share data) Number of Fair Warrant class/series: September 30, 2018 Issuance date Expiration date Exercise Series A 36,838 $ 365 October 8, 2013 October 8, 2023 $ 3.26 Series B 16,221 94 September 2, 2014 September 2, 2024 $ 7.84 Series C 18,854 130 December 22, 2015 December 22, 2025 $ 14.85 Series D 7,531 42 March 28, 2016 March 28, 2026 $ 21.24 Total preferred stock warrants 79,444 $ 631 Common stock warrants 64,127 $ 486 September 6, 2017 September 6, 2027 $ 6.24

Stock option plan (Tables)

Stock option plan (Tables)	12 Months Ended
	Sep. 30, 2019
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Activity Under The Equity Incentive Plans	Activity under the equity incentive plans during the years ended September 30, 2019, 2018 and 2017 is summarized below: Shares Options Weighted Weighted (years) Aggregate Outstanding at September 30, 2016 470,623 1,033,612 $ 4.93 8.81 $ 1,343,301 Additional shares authorized 1,035,414 — — Stock options granted (857,082 ) 857,082 8.61 Stock options exercised — (32,586 ) 5.54 Stock options forfeited 38,384 (38,384 ) 5.54 Outstanding at September 30, 2017 687,339 1,819,724 $ 6.63 9.14 $ 7,147,115 Additional shares authorized 905,786 — — Stock options granted (951,310 ) 951,310 10.96 Stock options exercised — (62,862 ) 5.37 Stock options forfeited 187,687 (187,687 ) 7.73 Early exercised options repurchased 9,639 — Forfeiture of restricted common stock 21,146 — — Outstanding at September 30, 2018 860,287 2,520,485 $ 8.22 8.38 $ 11,482,909 Additional shares authorized 2,494,700 — — Stock options granted (1,685,625 ) 1,685,625 25.53 Stock options exercised — (331,205 ) 6.67 Stock options forfeited 324,460 (324,460 ) 14.75 Restricted stock units granted (500,132 ) — — Early exercised options repurchased 442 — — Forfeiture of restricted stock units 26,743 — — Outstanding at September 30, 2019 1,520,875 3,550,445 $ 15.99 8.25 $ 31,997,934 Vested or expected to vest at September 30, 2019 3,550,445 $ 15.99 8.25 $ 31,997,934 Vested and exercisable at September 30, 2019 1,243,634 $ 7.77 7.01 $ 20,125,913
Schedule of Nonvested Restricted Stock Units Activity	Activity with respect to the Company’s restricted stock units during the year ended September 30, 2019 was as follows: (in thousands, except share and per share data) Number Weighted Weighted Aggregate Outstanding at September 30, 2018 — $ — — $ — Restricted stock units granted 500,132 26.12 3.87 13,059,488 Restricted stock units vested (11,019 ) 24.69 — — Restricted stock units forfeited (26,743 ) 25.92 — — Outstanding at September 30, 2019 462,370 26.16 3.91 8,959,223 Expected to vest at September 30, 2019 462,370 26.16 3.91 8,959,223
Total Stock-based Compensation Expense	Total stock-based compensation expense recognized was as follows: Year ended (in thousands) 2019 2018 2017 Cost of revenues $ 1,345 $ 376 $ 202 Research and development 2,378 705 575 Selling, general and administrative 7,447 1,880 1,114 Total stock-based compensation $ 11,170 $ 2,961 $ 1,891
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions	The fair value of options granted during the years ended September 30, 2019, 2018 and 2017, respectively, were calculated using the weighted average assumptions set forth below: Year ended 2019 2018 2017 Expected term (years) 6.41 6.25 6.25 Expected volatility 60.2 % 66.3 % 65.5 % Risk-free interest rate 2.72 % 2.65 % 2.02 % Dividend yield 0 % 0 % 0 %

Net loss per share attributab_2

Net loss per share attributable to common stockholders (Tables)	12 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Computation of the Company's Basic and Diluted Net Loss Per Share Attributable to Common Stockholders	The following table sets forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders: Year ended September 30, (in thousands, except share and per share data) 2019 2018 2017 Numerator: Net loss attributable to common stockholders $ (107,669 ) $ (71,236 ) $ (59,310 ) Denominator: Weighted-average shares used in computing net loss per share, basic and diluted 27,461,844 2,792,743 2,422,243 Net loss per share attributable to common stockholders, basic and diluted $ (3.92 ) $ (25.51 ) $ (24.49 )
Summary of Calculation of Diluted Net Loss Per Share	The potentially dilutive common shares that were excluded from the calculation of diluted net loss per share because their effect would have been antidilutive for the periods presented are as follows: Year ended September 30, 2019 2018 2017 Shares subject to options to purchase common stock 3,550,445 2,520,485 1,819,724 Unvested restricted shares of common stock 23,861 96,750 513,766 Unvested restricted stock units 462,370 — — Unvested shares of common stock issued upon early exercise of stock options 38,157 74,142 44,698 Shares subject to employee stock purchase plan 76,335 — — Shares subject to warrants to purchase common stock 26,385 64,127 64,127 Shares subject to warrants to purchase redeemable convertible preferred stock — 79,444 79,444 Shares of redeemable convertible preferred stock — 18,951,305 14,658,940 Total 4,177,553 21,786,253 17,180,699

Geographic, product and indus_2

Geographic, product and industry information (Tables)	12 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Summary of Revenue by Geographic Region	The table below sets forth revenues by geographic region, based on ship-to Year ended (in thousands) 2019 2018 2017 United States $ 35,936 $ 17,662 $ 8,243 EMEA 14,692 6,557 2,023 APAC 2,761 1,001 274 North America 996 207 227 Total $ 54,385 $ 25,427 $ 10,767
Summary of Revenue by Product	The table below sets forth revenues by products. Year ended (in thousands) 2019 2018 2017 Synthetic genes $ 26,712 $ 17,986 $ 8,122 Oligo pools 4,594 3,002 2,056 DNA libraries 2,036 1,771 517 NGS tools 21,043 2,668 72 Total $ 54,385 $ 25,427 $ 10,767
Summary of Revenue by Industry	Revenues by industry were as follows: Year ended September 30, (in thousands) 201 9 2018 2017 Industrial chemicals $ 21,927 $ 14,912 $ 6,702 Academic research 13,835 5,813 2,709 Healthcare 17,424 4,212 1,226 Agricultural 1,199 490 130 Total revenues $ 54,385 $ 25,427 $ 10,767

The company - Additional Inform

The company - Additional Information (Detail) - USD ($) $ in Thousands, shares in Millions	1 Months Ended
	May 31, 2019	Oct. 31, 2018	Apr. 30, 2016	Sep. 30, 2019	Sep. 30, 2018
Accumulated deficit				$ (318,524)	$ (210,855)
Proceeds of underwritten public offering common stock	$ 84,300
Genome Compiler Corporation [Member]
Shares issued in acquisition			0.4
IPO [Member]
Proceeds of underwritten public offering common stock		$ 69,600

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Deferred offering costs included in non-current assets		$ 3,700
Credit period granted to customers	30 days
Depreciation and amortization expense	$ 6,100	5,500	$ 4,800
Capitalised software development costs	2,300	1,900
Impairment of long lived assets	0	0		$ 0
Contract assets	0	0
Contract liabilities	0	0
Advertising and promotion expenses	$ 1,300	$ 900	100
Contract payments research and development received			0
Adjustment to additional paid in capital warrants issued			$ 486
Common stock warrants issued	0	0
Defense Advanced Research Project Agency [Member]
Contract payments research and development received	$ 500	$ 300
Software and Software Development Costs [Member]
Capitalised sofware developed useful life	3 years

Summary of significant accoun_5

Summary of significant accounting policies - Schedule Of Estimated Lives of Property And Equipment (Detail)	12 Months Ended
	Sep. 30, 2019
Laboratory equipment
Property, Plant and Equipment, Useful Life	5 years
Furniture, fixtures and other equipment
Property, Plant and Equipment, Useful Life	5 years
Computer equipment
Property, Plant and Equipment, Useful Life	3 years
Computer software
Property, Plant and Equipment, Useful Life	3 years
Leasehold improvements
Property, Plant and Equipment, Estimated Useful Lives	Lesser of useful life or<br/>facilities’ lease term.

Summary of significant accoun_6

Summary of significant accounting policies - Schedule of concentration of risk (Detail) - Customer A [Member] - Customer Concentration Risk [Member]	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Sales Revenue, Net [Member]
Concentration Risk, Percentage	17.00%	34.00%	40.00%
Accounts Receivable [Member]
Concentration Risk, Percentage	13.00%	27.00%

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Summary of Cash, Cash Equivalents and Restricted Cash (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018		Sep. 30, 2017		Sep. 30, 2016	[1]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 46,735	$ 80,757		$ 31,227
Restricted cash, non-current	579	579		202
Restricted cash, current (within prepaid expenses and other current assets)	84	201		144
Total cash, cash equivalents and restricted cash	$ 47,398	$ 81,537	[1]	$ 31,573	[1]	$ 29,062
[1]	Adjusted to reflect the retrospective adoption of Accounting Standards Update (ASU) 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash.

Fair value measurement - Cash A

Fair value measurement - Cash And Cash Equivalents And Available For Sale Securities At Fair Value (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Cash And Cash Equivalents At Amortized Cost	$ 46,735	$ 80,757
Available-for-sale Securities, Amortized Cost Basis	91,323
Cash And Cash Equivalents And Short Term Invesmtnets Amortized Cost	138,058	80,757
Available-for-sale Securities, Gross Unrealized Gain	49
Available for sale Securities Gross Unrealized Gain Loss	49
Cash and Cash Equivalents, at Carrying Value	46,735	80,757	$ 31,227
Short-term Investments	91,372
Cash, Cash Equivalents, and Short-term Investments	$ 138,107	$ 80,757

Fair Value Measurement - Summar

Fair Value Measurement - Summary of Company's Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Assets
Assets, Totals	$ 138,107	$ 80,757
Corporate bonds [Member]
Assets
Assets, Totals	8,530
Commercial Paper [Member]
Assets
Assets, Totals	28,361
US Government Treasury Bills [Member]
Assets
Assets, Totals	54,482
Redeemable Convertible Preferred Stock Warrant Liability [Member]
Liabilities
Redeemable convertible preferred stock warrant liability		631
Cash [Member]
Assets
Assets, Totals	19,344	46,823
Money Market Funds [Member]
Assets
Assets, Totals	27,390	33,934
Fair Value, Inputs, Level 1 [Member]
Assets
Assets, Totals	101,216	80,757
Fair Value, Inputs, Level 1 [Member] | US Government Treasury Bills [Member]
Assets
Assets, Totals	54,482
Fair Value, Inputs, Level 1 [Member] | Cash [Member]
Assets
Assets, Totals	19,344	46,823
Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Assets
Assets, Totals	27,390	33,934
Fair Value, Inputs, Level 2 [Member]
Assets
Assets, Totals	36,891
Fair Value, Inputs, Level 2 [Member] | Corporate bonds [Member]
Assets
Assets, Totals	8,530
Fair Value, Inputs, Level 2 [Member] | Commercial Paper [Member]
Assets
Assets, Totals	$ 28,361
Fair Value, Inputs, Level 3 [Member] | Redeemable Convertible Preferred Stock Warrant Liability [Member]
Liabilities
Redeemable convertible preferred stock warrant liability		$ 631

Fair Value Measurement - Summ_2

Fair Value Measurement - Summary of Reconciliation of Beginning and Ending Balances of the Level 3 Instruments (Detail) - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Fair Value, Instruments Classified in Shareholders' Equity Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, beginning balance	$ 631	$ 644	$ 383
Conversion of redeemable convertible preferred stock warrants to common stock warrants	(631)
Change in fair value recorded in other income (expense), net		(13)	261
Fair value, ending balance		631	644
Series A Redeemable Convertible Preferred Stock [Member]
Fair Value, Instruments Classified in Shareholders' Equity Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, beginning balance	365	331	184
Conversion of redeemable convertible preferred stock warrants to common stock warrants	(365)
Change in fair value recorded in other income (expense), net		34	147
Fair value, ending balance		365	331
Series B Redeemable Convertible Preferred Stock [Member]
Fair Value, Instruments Classified in Shareholders' Equity Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, beginning balance	94	110	57
Conversion of redeemable convertible preferred stock warrants to common stock warrants	(94)
Change in fair value recorded in other income (expense), net		(16)	53
Fair value, ending balance		94	110
Series C Redeemable Convertible Preferred Stock [Member]
Fair Value, Instruments Classified in Shareholders' Equity Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, beginning balance	130	152	108
Conversion of redeemable convertible preferred stock warrants to common stock warrants	(130)
Change in fair value recorded in other income (expense), net		(22)	44
Fair value, ending balance		130	152
Series D Redeemable Convertible Preferred Stock [Member]
Fair Value, Instruments Classified in Shareholders' Equity Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value, beginning balance	42	51	34
Conversion of redeemable convertible preferred stock warrants to common stock warrants	(42)
Change in fair value recorded in other income (expense), net		(9)	17
Fair value, ending balance		$ 42	$ 51

Balance sheet components - Sche

Balance sheet components - Schedule Of Accounts Notes Loans And Financing Receivable (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Trade Receivables	$ 11,085	$ 5,439
Other Receivables	1,313	75
Allowance for Doubtful Accounts	(294)	(95)
Accounts receivable, net	$ 12,104	$ 5,419

Balance sheet components - Summ

Balance sheet components - Summary of Inventory (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Balance Sheet Related Disclosures [Abstract]
Raw Materials	$ 4,900	$ 2,988
Work-in-process	1,157	2,273
Finished Goods	1,273	767
Total inventories	$ 7,330	$ 6,028

Balance sheet components - Sc_2

Balance sheet components - Schedule Of Property Plant And Equipment (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 43,828	$ 29,583
Less: Accumulated depreciation and amortization	(22,993)	(17,252)
Property, Plant and Equipment, Net	20,835	12,331
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	26,021	18,865
Furniture, fixtures and other equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,760	613
Computer equipment
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	2,777	2,137
Computer software
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,507	3,094
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,772	3,340
Construction in progress
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 5,991	$ 1,534

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Goodwill And Intangible Assets [Line Items]
Changes in carrying value of goodwill	$ 0	$ 0
Maximum [Member]
Goodwill And Intangible Assets [Line Items]
Total amortization expense related to intangible assets	$ 200,000	$ 200,000	$ 200,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Summary of Intangible Assets Balances (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Acquired Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 1,240	$ 1,240
Accumulated amortization	(732)	(528)
Net book value	$ 508	$ 712
Developed Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	6 years	6 years
Gross carrying amount	$ 1,220	$ 1,220
Accumulated amortization	(712)	(508)
Net book value	$ 508	$ 712
Tradenames & Trademarks [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Useful life in years	2 years	2 years
Gross carrying amount	$ 20	$ 20
Accumulated amortization	$ (20)	$ (20)

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Schedule of Finite Lived Intangible Assets Future Amortization Expense (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
2020	$ 203
2021	203
2022	102
Net book value	$ 508	$ 712

Long-term debt - Additional Inf

Long-term debt - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2019	Jul. 31, 2019
Exercise Price Of Warrants				$ 7.84	$ 6.24
Proceeds from long term debt	[1]		$ 2,174
Fourth Amended and Restated Loan and Security Agreement [Member]
Debt instrument fee amount			$ 700
SVB [Member] | Prime Rate [Member]
Debt instrument variable interest rate spread			3.00%
SVB [Member] | Revolving Credit Facility [Member]
Proceeds from long term line of credit			$ 10,000
SVB [Member] | Revolving Credit Facility [Member] | Floating Interest Rate [Member]
Debt instrument variable interest rate spread			1.00%
Debt Periodic Payment			principal amount outstanding under the revolving line would accrue interest at a floating per annum rate equal to one percentage point (1.00%) above the prime rate, which interest shall be payable monthly.
SVB [Member] | Fourth Amended and Restated Loan and Security Agreement [Member]
Debt instrument principal amount			$ 20,000
Exercise Price Of Warrants			$ 6.24
Debt instrument term			51 months
SVB [Member] | Fourth Amended and Restated Loan and Security Agreement [Member] | Prime Rate [Member]
Debt instrument description of interest rate			interest rate of prime plus 3.00%
SVB [Member] | Tranche One [Member] | Fourth Amended and Restated Loan and Security Agreement [Member]
Debt instrument principal amount			$ 10,000
Warrants To Purchase Common Stock			64,127
Proceeds from long term debt			$ 10,000
SVB [Member] | Tranche Two [Member] | Fourth Amended and Restated Loan and Security Agreement [Member]
Debt instrument principal amount			5,000
Debt Instrument Maturity		Jan. 31, 2018
SVB [Member] | Tranche Three [Member] | Fourth Amended and Restated Loan and Security Agreement [Member]
Debt instrument principal amount			5,000
Debt Instrument Maturity		Jun. 30, 2018
SVB [Member] | Prior Loan Refinance | Tranche One [Member] | Fourth Amended and Restated Loan and Security Agreement [Member]
Proceeds from long term debt			7,800
SVB [Member] | New Advance | Tranche One [Member] | Fourth Amended and Restated Loan and Security Agreement [Member]
Proceeds from long term debt			$ 2,200
[1]	Adjusted to reflect the retrospective adoption of Accounting Standards Update (ASU) 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash.

Long-term debt - Schedule Of Ma

Long-term debt - Schedule Of Maturities Of Long Term Debt (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Debt Instrument [Line Items]
2020	$ 3,333
2021	3,333
2022	834
Long-term Debt	7,500
2020	486
2021	214
2022	11
Interest Payable On Long Term Debt	711
2020	3,819
2021	3,547
2022	845
Long Term Debt Maturities Repayment Principal And Interest Total	8,211
Less: Interest	711
Long-term Debt	7,500
Less unamortized debt discount	(269)
Add: accretion of final payment fee	502
Long Term Debt Including Interest And Fee Payable	7,733
Accrued Expenses [Member]
Debt Instrument [Line Items]
Interest Payable On Long Term Debt	(711)
Less: Interest	$ (711)

Commitments and contingencies -

Commitments and contingencies - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Operating lease rental expenses	$ 4.9	$ 2.5	$ 2.2
Property Subject to Operating Lease [Member]
Operating lease prepaid rent	1.6	0
Operating lease deferred rent	$ 0	$ 0.1

Commitments and contingencies_2

Commitments and contingencies - Schedule Of Future Minimum Rental Payments For Operating Leases (Detail) $ in Thousands	Sep. 30, 2019USD ($)
Commitments and Contingencies Disclosure [Abstract]
2020	$ 6,671
2021	5,909
2022	5,979
2023	6,064
2024	6,029
Thereafter	10,067
Total minimum lease payments	$ 40,719

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Raw materials purchased from related party investor	$ 3.2	$ 2.3	$ 2
Description of related party transactions	During the year ended September 30, 2019, the Company purchased raw materials from a related party investor in the amount of $3.2 million. Payable balances and cash receipts and receivable balances with the related party were immaterial as of September 30, 2019.	During the year ended September 30, 2018, the Company purchased raw materials from a related party investor in the amount of $2.3 million. Payable balances and cash receipts and receivable balances with the related party were immaterial as of September 30, 2018.
Series D Redeemable Convertible Preferred Stock [Member]
Temporary equity issued	0	10,326,454	170,085

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Provision for income taxes	$ 292	$ 242	$ 280
Expiration year	2033
Effective Income Tax Rate	21.00%	24.00%	35.00%
Limitation description	For net operating losses generated in the years beginning after December 31, 2017, utilization is limited to 80% of taxable income with an unlimited carryforward period.
Tax credit carryforward, limitations on use	For net operating losses generated in the years beginning after December 31, 2017, utilization is limited to 80% of taxable income with an immaterial provision for income taxesunlimited carryforward period. The Company recognized the effect of the tax law changes in the period of enactment, which required a remeasurement of its U.S. deferred tax assets and liabilities
Tax Year 2018 [Member]
Effective Income Tax Rate		35.00%
Tax Year 2019 [Member]
Effective Income Tax Rate	21.00%
Domestic Tax Authority [Member]
Operating loss carry forwards	$ 293,600
Domestic Tax Authority [Member] | Research Tax Credit Carryforward [Member]
Tax credit carry forwards	5,700
State and Local Jurisdiction [Member]
Operating loss carry forwards	183,400
State and Local Jurisdiction [Member] | Research Tax Credit Carryforward [Member]
Tax credit carry forwards	$ 5,100

Income taxes - Schedule Of Defe

Income taxes - Schedule Of Deferred Tax Assets And Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Sep. 30, 2018
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 73,341	$ 49,801
Research and development credit carryforwards	6,831	4,621
Other	4,553	1,919
Gross deferred tax assets	84,725	56,341
Less: Valuation allowance	(84,598)	(56,158)
Net deferred tax assets	127	183
Fixed assets	(1)	(1)
Intangible assets	(126)	(182)
Gross deferred tax liabilities	(127)	(183)
Total net deferred tax asset

Income taxes - Schedule Of Effe

Income taxes - Schedule Of Effective Income Tax Rate Reconciliation (Detail)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Tax expense computed at the federal statutory rate	21.00%	24.00%	35.00%
Change in valuation allowance	(22.00%)	4.00%	(35.00%)
Research and development credit benefit	1.00%	1.00%	1.00%
Change in federal tax rate		(28.00%)
Other expenses		(1.00%)	(1.00%)
Total income tax expense

Income taxes - Schedule Of Unre

Income taxes - Schedule Of Unrecognized Tax Benefits Roll Forward (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Balance	$ 2,249	$ 1,625	$ 822
Increases related to tax positions during the year	1,042	624	562
Increases related to tax positions in prior years			241
Balance	$ 3,291	$ 2,249	$ 1,625

Warrants - Summary of Issued Wa

Warrants - Summary of Issued Warrants for Its Redeemable Convertible Preferred Stock and Common Stock (Detail) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Jul. 31, 2019	Nov. 30, 2018
Class of Warrant or Right [Line Items]
Fair Value	[1]		$ (13)	$ 261
Exercise price per share		$ 7.84			$ 6.24
Warrants One [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants						36,838
Exercise price per share						$ 3.26
Warrants Two [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants						32,063
Exercise price per share						$ 6.24
Series A Redeemable Convertible Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants			36,838
Fair Value			$ 365
Issuance date			Oct. 8, 2013
Expiration date			Oct. 8, 2023
Exercise price per share			$ 3.26
Series B Redeemable Convertible Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants			16,221
Fair Value			$ 94
Issuance date			Sep. 2, 2014
Expiration date			Sep. 2, 2024
Exercise price per share			$ 7.84
Series C Redeemable Convertible Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants			18,854
Fair Value			$ 130
Issuance date			Dec. 22, 2015
Expiration date			Dec. 22, 2025
Exercise price per share			$ 14.85
Series D Redeemable Convertible Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants			7,531
Fair Value			$ 42
Issuance date			Mar. 28, 2016
Expiration date			Mar. 28, 2026
Exercise price per share			$ 21.24
Redeemable Convertible Preferred Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants			79,444
Fair Value			$ 631
Common Stock [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants		26,385	64,127
Fair Value			$ 486
Issuance date			Sep. 6, 2017
Expiration date			Sep. 6, 2027
Exercise price per share			$ 6.24
Common Stock [Member] | Warrants One [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants		18,854
Issuance date		Dec. 22, 2015
Expiration date		Dec. 22, 2025
Exercise price per share		$ 14.85
Common Stock [Member] | Warrants Two [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants		7,531
Issuance date		Mar. 28, 2016
Expiration date		Mar. 28, 2026
Exercise price per share		$ 21.24
[1]	Adjusted to reflect the retrospective adoption of Accounting Standards Update (ASU) 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash.

Warrants - Additional Informati

Warrants - Additional Information (Detail) - $ / shares	1 Months Ended
	Sep. 30, 2019	Jul. 31, 2019	Nov. 30, 2018
Class of Warrant or Right [Line Items]
Net exercise of stock warrants	16,221	32,064	68,901
Exercise price per share	$ 7.84	$ 6.24
Common stock issued for cashless exercise	12,019	25,422	57,122
Warrants One [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants			36,838
Exercise price per share			$ 3.26
Warrants Two [Member]
Class of Warrant or Right [Line Items]
Number of shares underlying warrants			32,063
Exercise price per share			$ 6.24

Stock option plan - Additional

Stock option plan - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions	Sep. 26, 2018	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, stock options		$ 24.8
Unrecognized stock-based compensation expense, period for recognition		3 years 4 months 24 days
Options Grant date fair value		$ 15.06	$ 7.08	$ 6.63
Vesting Rights Percentage		25.00%
Shares subject to right of repurchase		38,157
2018 Equity Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum annual increase in share reserved for issuance	999,900
Annual automatic Increase in share reserved for issuance	4.00%
2018 Equity Incentive Plan [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock shares may be issued	5,856,505
2018 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum annual increase in share reserved for issuance	249,470
Annual automatic Increase in share reserved for issuance	1.00%
Aggregate number of common stock shares reserved for issuance	275,225
2018 ESPP [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of payroll deduction to purchase common stock	15.00%
2015 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
ESPP eligible employee common stock purchase price ratio	85.00%
Restricted Stock Units (RSUs) [Member] | 2018 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost, stock options		$ 10.2
Unrecognized stock-based compensation expense, period for recognition		3 years 11 months 26 days

Stock option plan - Activity Un

Stock option plan - Activity Under The Equity Incentive Plans (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2016
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Shares available, Outstanding Beginning Balance	860,287	687,339	470,623
Shares available, Additional shares authorized	2,494,700	905,786	1,035,414
Shares available, Stock options granted	(1,685,625)	(951,310)	(857,082)
Shares available, Stock options forfeited	324,460	187,687	38,384
Shares available, Restricted stock units granted	(500,132)
Shares available, Early exercised options repurchased	442	9,639
Shares available, Forfeiture of restricted stock units	26,743	21,146
Shares available, Outstanding Ending Balance	1,520,875	860,287	687,339	470,623
Number of options, Outstanding beginning balance	2,520,485	1,819,724	1,033,612
Options outstanding, Stock options granted	1,685,625	951,310	857,082
Options outstanding, Stock options exercised	(331,205)	(62,862)	(32,586)
Options outstanding, Stock options forfeited	(324,460)	(187,687)	(38,384)
Number of options, Outstanding ending balance	3,550,445	2,520,485	1,819,724	1,033,612
Weighted average exercise price per share, Outstanding Beginning Balance	$ 8.22	$ 6.63	$ 4.93
Weighted average exercise price per share, Stock options granted	25.53	10.96	8.61
Weighted average exercise price per share, Stock options exercised	6.67	5.37	5.54
Weighted average exercise price per share, Stock options forfeited	14.75	7.73	5.54
Weighted average exercise price per share, Outstanding Ending Balance	$ 15.99	$ 8.22	$ 6.63	$ 4.93
Weighted average remaining contractual term, Outstanding	8 years 3 months	8 years 4 months 17 days	9 years 1 month 20 days	8 years 9 months 21 days
Aggregate intrinsic value, Outstanding			$ 1,343,301
Aggregate intrinsic value, Outstanding Vested or expected to vest and exercisable	$ 31,997,934	$ 11,482,909	$ 7,147,115
Options outstanding, Vested or expected to vest	3,550,445
Weighted average exercise price per share, Vested or expected to vest	$ 15.99
Weighted average remaining contractual term, Vested or expected to vest	8 years 3 months
Aggregate intrinsic value, Vested or expected to vest	$ 31,997,934
Options outstanding, Vested and exercisable	1,243,634
Weighted average exercise price per share, Vested and exercisable	$ 7.77
Weighted average remaining contractual term,Vested and exercisable	7 years 3 days
Aggregate intrinsic value, Vested and exercisable	$ 20,125,913

Stock option plan - Schedule of

Stock option plan - Schedule of Nonvested Restricted Stock Units Activity (Detail) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 30, 2019USD ($)$ / sharesshares
Nonvested Restricted Stock Units Activity [Line Items]
Weighted average grant date fair value price per share, Expected to vest | $ / shares	$ 26.16
Restricted Stock Units (RSUs) [Member]
Nonvested Restricted Stock Units Activity [Line Items]
Number of shares, granted | shares	500,132
Number of shares, vested | shares	(11,019)
Number of shares, forfeited | shares	(26,743)
Number of shares, Outstanding Ending Balance | shares	462,370
Expected to vest, Outstanding | shares	462,370
Weighted average grant date fair value price per share, granted | $ / shares	$ 26.12
Weighted average grant date fair value price per share, vested | $ / shares	24.69
Weighted average grant date fair value price per share, forfeited | $ / shares	25.92
Weighted average grant date fair value price per share, Outstanding Ending Balance | $ / shares	$ 26.16
Weighted average remaining contractual term, granted	3 years 10 months 13 days
Weighted average remaining contractual term, Expected to vest	3 years 10 months 27 days
Aggregate intrinsic value, Granted | $	$ 13,059,488
Aggregate intrinsic value, Outstanding | $	8,959,223
Aggregate intrinsic value, Expected to vest | $	$ 8,959,223

Stock option plan - Total Stock

Stock option plan - Total Stock-based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$ 11,170	$ 2,961	$ 1,891
Cost of Revenues [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	1,345	376	202
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	2,378	705	575
Selling, General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$ 7,447	$ 1,880	$ 1,114

Stock option plan - Schedule _2

Stock option plan - Schedule of Share Based Payment Award Stock Options Valuation Assumptions (Detail)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Expected term (years)	6 years 4 months 27 days	6 years 3 months	6 years 3 months
Expected volatility	60.20%	66.30%	65.50%
Risk-free interest rate	2.72%	2.65%	2.02%
Dividend yield	0.00%	0.00%	0.00%

Net Loss Per Share Attributab_3

Net Loss Per Share Attributable to Common Stockholders - Computation of the Company's Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Numerator:
Net loss attributable to common stockholders	$ (107,669)	$ (71,236)	$ (59,310)
Denominator:
Weighted-average shares used in computing net loss per share attributable to common stockholders—basic and diluted	27,461,844	2,792,743	2,422,243
Net loss per share attributable to common stockholders, basic and diluted	$ (3.92)	$ (25.51)	$ (24.49)

Net Loss Per Share Attributab_4

Net Loss Per Share Attributable to Common Stockholders - Summary of Calculation of Diluted Net Loss Per Share (Detail) - shares	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	4,177,553	21,786,253	17,180,699
Options To Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	3,550,445	2,520,485	1,819,724
Restricted Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	23,861	96,750	513,766
Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	462,370
Early Exercise Of Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	38,157	74,142	44,698
Warrants To Purchase Common Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	26,385	64,127	64,127
Warrants to Purchase Redeemable Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		79,444	79,444
Redeemable Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount		18,951,305	14,658,940
Employee Stock Purchase Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share amount	76,335

Geographic, Product and Indus_3

Geographic, Product and Industry Information - Summary of Revenue by Geographic Region (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Revenue	$ 54,385	$ 25,427	$ 10,767
United States [Member]
Segment Reporting Information [Line Items]
Revenue	35,936	17,662	8,243
EMEA [Member]
Segment Reporting Information [Line Items]
Revenue	14,692	6,557	2,023
Asia Pacific [Member]
Segment Reporting Information [Line Items]
Revenue	2,761	1,001	274
North America [Member]
Segment Reporting Information [Line Items]
Revenue	$ 996	$ 207	$ 227

Geographic, Product and Indus_4

Geographic, Product and Industry Information - Summary of Revenue by Product (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Revenue	$ 54,385	$ 25,427	$ 10,767
Synthetic Genes [Member]
Segment Reporting Information [Line Items]
Revenue	26,712	17,986	8,122
Oligo Pools [Member]
Segment Reporting Information [Line Items]
Revenue	4,594	3,002	2,056
DNA Libraries [Member]
Segment Reporting Information [Line Items]
Revenue	2,036	1,771	517
NGS Tools [Member]
Segment Reporting Information [Line Items]
Revenue	$ 21,043	$ 2,668	$ 72

Geographic, Product and Indus_5

Geographic, Product and Industry Information - Summary of Revenue by Industry (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Segment Reporting Information [Line Items]
Revenue	$ 54,385	$ 25,427	$ 10,767
Industrial Chemicals [Member]
Segment Reporting Information [Line Items]
Revenue	21,927	14,912	6,702
Academic Research [Member]
Segment Reporting Information [Line Items]
Revenue	13,835	5,813	2,709
Health Care [Member]
Segment Reporting Information [Line Items]
Revenue	17,424	4,212	1,226
Agricultural [Member]
Segment Reporting Information [Line Items]
Revenue	$ 1,199	$ 490	$ 130

Geographic, Product and Indus_6

Geographic, Product and Industry Information - Additional Information (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Sep. 30, 2018
United States [Member]
Segment Reporting Information [Line Items]
Long-lived assets	$ 19.8	$ 11.9
Non-US [Member]
Segment Reporting Information [Line Items]
Long-lived assets	$ 1	$ 0.4