Sonos (SONO) 10-K 26 Nov 19 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Sep. 28, 2019	Nov. 08, 2019	Mar. 29, 2019
Document Information [Abstract]
Entity Registrant Name	Sonos Inc
Entity Central Index Key	0001314727
Current Fiscal Year End Date	--09-28
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Sep. 28, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		108,418,445
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Smaller Reporting Company	false
Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 760.8

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 28, 2019	Sep. 29, 2018
Current assets:
Cash and cash equivalents	$ 338,641	$ 220,930
Restricted cash	179	190
Accounts receivable, net of allowances of $21,306 and $12,626 as of September 28, 2019 and September 29, 2018	102,743	73,214
Inventories	219,784	193,193
Prepaid and other current assets	17,762	10,073
Total current assets	679,109	497,600
Property and equipment, net	78,139	85,371
Deferred tax assets	1,154	941
Other noncurrent assets	3,203	3,586
Total assets	761,605	587,498
Current liabilities:
Accounts payable	251,941	195,159
Accrued expenses	69,856	38,687
Accrued compensation	41,142	33,371
Short-term debt	8,333	6,667
Deferred revenue	13,654	11,615
Other current liabilities	17,548	10,858
Total current liabilities	402,474	296,357
Long-term debt	24,840	33,097
Deferred revenue	42,795	39,352
Other noncurrent liabilities	10,568	10,334
Total liabilities	480,677	379,140
Commitments and contingencies (Note 11)
Stockholders’ equity:
Common stock, $0.001 par value; 500,000,000 and 151,458,824 shares authorized, 109,623,417 and 100,868,250 shares issued 108,602,642 and 100,061,210 shares outstanding as of September 28, 2019 and September 29, 2018, respectively	110	101
Treasury stock, 1,020,775 and 807,040 shares at cost as of September 28, 2019 and September 29, 2018, respectively	(13,498)	(11,072)
Additional paid-in capital	502,757	424,617
Accumulated deficit	(208,377)	(203,611)
Accumulated other comprehensive loss	(64)	(1,677)
Total stockholders' equity	280,928	208,358
Total liabilities and stockholders’ equity	$ 761,605	$ 587,498

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 28, 2019	Sep. 29, 2018
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 21,306	$ 12,626
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, authorized (in shares)	500,000,000	151,458,824
Common stock, shares issued (in shares)	109,623,417	100,868,250
Common stock, shares outstanding (in shares)	108,602,642	100,061,210
Treasury stock, shares at cost (in shares)	1,020,775	807,040

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Income Statement [Abstract]
Revenue	$ 1,260,823	$ 1,137,008	$ 992,526
Cost of revenue	733,480	647,700	536,461
Gross profit	527,343	489,308	456,065
Operating expenses
Research and development	171,174	142,109	124,394
Sales and marketing	247,599	270,869	270,162
General and administrative	102,871	85,205	77,118
Total operating expenses	521,644	498,183	471,674
Operating income (loss)	5,699	(8,875)	(15,609)
Other income (expense), net
Interest income	4,349	731	120
Interest expense	(2,499)	(5,242)	(4,380)
Other income (expense), net	(8,625)	(1,162)	3,361
Total other expense, net	(6,775)	(5,673)	(899)
Loss before provision for (benefit from) income taxes	(1,076)	(14,548)	(16,508)
Provision for (benefit from) income taxes	3,690	1,056	(2,291)
Net loss	(4,766)	(15,604)	(14,217)
Net loss attributable to common stockholders, basic and diluted:	$ (4,766)	$ (15,604)	$ (14,217)
Net loss per share attributable to common stockholders, basic and diluted (in dollars per share)	$ (0.05)	$ (0.24)	$ (0.25)
Weighted-average shares used in computing net loss per share attributable to common stockholders, basic and diluted (in shares)	103,783,006	65,706,215	56,314,546
Total comprehensive loss
Net loss	$ (4,766)	$ (15,604)	$ (14,217)
Change in foreign currency translation adjustment	1,613	488	(2,486)
Comprehensive loss	$ (3,153)	$ (15,116)	$ (16,703)

CONSOLIDATED STATEMENTS OF REDE

CONSOLIDATED STATEMENTS OF REDEEMABLE CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Treasury Stock	Accumulated Deficit	Accumulated Other Comprehensive Loss
Redeemable Convertible Preferred Stock, beginning balance (in shares) at Oct. 01, 2016	32,482,590
Redeemable Convertible Preferred Stock, beginning balance at Oct. 01, 2016	$ 90,341
Redeemable Convertible Preferred Stock, ending balance (in shares) at Sep. 30, 2017	32,482,590
Redeemable Convertible Preferred Stock, ending balance at Sep. 30, 2017	$ 90,341
Balances, beginning of period (in shares) at Oct. 01, 2016		54,841,214		(7,780)
Balances, beginning of period at Oct. 01, 2016	(28,788)	$ 55	$ 144,771	$ (145)	$ (173,790)	$ 321
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net exercise of Series C preferred stock warrants (in shares)		742,034
Net exercise of Series C preferred stock warrants	10,078	$ 1	10,077
Exercise of stock options (in shares)		3,756,088
Issuance of common stock pursuant to equity incentive plans	8,906	$ 3	8,903
Retirement of treasury stock	(10,016)			$ (10,016)
Purchase of treasury stock (in shares)				(738,682)
Purchase of treasury stock	0
Stock-based compensation expense	36,550		36,550
Net loss	(14,217)				(14,217)
Change in foreign currency translation adjustment	(2,486)					(2,486)
Balances, ending of period (in shares) at Sep. 30, 2017		59,339,336		(746,462)
Balances, ending of period at Sep. 30, 2017	$ 27	$ 59	200,301	$ (10,161)	(188,007)	(2,165)
Increase (Decrease) in Temporary Equity [Roll Forward]
Conversion of redeemable convertible preferred stock upon initial public offering (in shares)	(32,482,590)
Conversion of redeemable convertible preferred stock upon initial public offering	$ (90,341)
Redeemable Convertible Preferred Stock, ending balance (in shares) at Sep. 29, 2018	0
Redeemable Convertible Preferred Stock, ending balance at Sep. 29, 2018	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common, net of issuance/offering costs (in shares)		6,388,888
Issuance of common, net of issuance/offering costs	86,027	$ 6	86,021
Conversion of redeemable convertible preferred stock upon initial public offering (in shares)		32,482,590
Conversion of redeemable convertible preferred stock upon initial public offering	90,341	$ 33	90,308
Exercise of stock options (in shares)		2,657,436
Issuance of common stock pursuant to equity incentive plans	9,345	$ 3	9,342
Purchase of treasury stock (in shares)				(60,578)
Purchase of treasury stock	(911)			$ (911)
Stock-based compensation expense	38,645		38,645
Net loss	(15,604)				(15,604)
Change in foreign currency translation adjustment	$ 488					488
Balances, ending of period (in shares) at Sep. 29, 2018	100,061,210	100,868,250		(807,040)
Balances, ending of period at Sep. 29, 2018	$ 208,358	$ 101	424,617	$ (11,072)	(203,611)	(1,677)
Redeemable Convertible Preferred Stock, ending balance (in shares) at Sep. 28, 2019	0
Redeemable Convertible Preferred Stock, ending balance at Sep. 28, 2019	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of stock options (in shares)	7,925,897	8,755,167
Issuance of common stock pursuant to equity incentive plans	$ 31,574	$ 9	31,565
Purchase of treasury stock (in shares)				(213,735)
Purchase of treasury stock	(2,426)			$ (2,426)
Stock-based compensation expense	46,575		46,575
Net loss	(4,766)				(4,766)
Change in foreign currency translation adjustment	$ 1,613					1,613
Balances, ending of period (in shares) at Sep. 28, 2019	108,602,642	109,623,417		(1,020,775)
Balances, ending of period at Sep. 28, 2019	$ 280,928	$ 110	$ 502,757	$ (13,498)	$ (208,377)	$ (64)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Cash flows from operating activities
Net loss	$ (4,766)	$ (15,604)	$ (14,217)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation	36,415	39,358	35,014
Stock-based compensation expense	46,575	38,645	36,550
Other	2,713	1,676	713
Deferred income taxes	(268)	152	1,443
Foreign currency transaction (gain) loss	4,035	941	(3,568)
Changes in operating assets and liabilities:
Accounts receivable, net	(32,078)	(26,505)	(2,727)
Inventories, net	(31,796)	(80,107)	(60,270)
Other assets	(7,605)	(2,140)	36
Accounts payable and accrued expenses	85,878	66,473	54,895
Accrued compensation	8,231	1,625	5,123
Deferred revenue	6,165	5,566	9,411
Other liabilities	7,137	490	1,557
Net cash provided by operating activities	120,636	30,570	63,960
Cash flows from investing activities
Purchases of property and equipment	(23,222)	(35,747)	(33,553)
Net cash used in investing activities	(23,222)	(35,747)	(33,553)
Cash flows from financing activities
Proceeds from initial public offering, net of underwriting discounts and commissions	0	90,562	0
Payments of offering costs	(585)	(3,950)	0
Proceeds from issuance of common stock, net of issuance costs	0	0	10,078
Proceeds from exercise of stock options	31,574	9,345	8,906
Payments for purchase of treasury stock	(2,426)	(911)	(10,016)
Proceeds from borrowings, net of borrowing costs	0	69,748	14,987
Repayments of borrowings	(6,667)	(70,000)	0
Payments for debt extinguishment costs	0	(420)	0
Net cash provided by financing activities	21,896	94,374	23,955
Effect of exchange rate changes on cash, cash equivalents and restricted cash	(1,610)	1,135	1,329
Net increase in cash, cash equivalents, and restricted cash	117,700	90,332	55,691
Cash, cash equivalents, and restricted cash
Beginning of period	221,120	130,788	75,097
End of period	338,820	221,120	130,788
Supplemental disclosure
Cash paid for interest	2,517	3,750	4,114
Cash paid for taxes, net of refunds	3,570	1,430	461
Supplemental disclosure of non-cash investing and financing activities
Conversion of redeemable convertible preferred stock to common stock	0	90,341	0
Purchases of property and equipment, accrued but not paid	11,687	4,075	9,665
Deferred offering costs in accounts payable and accrued expenses	$ 0	$ 585	$ 0

Business overview

Business overview	12 Months Ended
	Sep. 28, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business overview	Business overview Description of business Sonos, Inc. and its wholly owned subsidiaries (collectively, "Sonos" or the "Company") designs, develops, manufactures and sells multi-room audio products. The Sonos sound system provides customers with an immersive listening experience created by the design of its speakers and components, a proprietary software platform and the ability to stream content from a variety of sources over the customer’s wireless network or over Bluetooth. The Company’s products are sold through third-party retail stores, including custom installers of home audio systems. The Company also sells through select e-commerce retailers and its website sonos.com. The Company’s products are distributed in over 50 countries through its wholly owned subsidiaries: Sonos Europe B.V., Beijing Sonos Technology Co., Ltd., Sonos Japan GK and Sonos Australia Pty Ltd., located in the Netherlands, China, Japan and Australia, respectively. Initial public offering On August 6, 2018, the Company completed its initial public offering ("IPO") of 15,972,221 shares of its common stock. The shares were sold at the IPO price of $ 15.00 per share for net proceeds of $ 90.6 million, after deducting underwriting discounts and commissions of $ 5.3 million and offering costs of approximately $ 4.6 million. Upon completion of the IPO, all outstanding shares of the Company's redeemable convertible preferred stock automatically converted into 32,482,590 shares of common stock on a one -for-one basis.

Summary of significant accounti

Summary of significant accounting policies	12 Months Ended
	Sep. 28, 2019
Accounting Policies [Abstract]
Summary of significant accounting policies	Summary of significant accounting policies Basis of presentation and preparation The consolidated financial statements, which include the accounts of Sonos, Inc. and its wholly owned subsidiaries, have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP"). All intercompany accounts and transactions have been eliminated in consolidation. Certain prior period amounts have been reclassified to conform to the current period presentation. The Company operates on a 52- or 53- week fiscal year ending on the Saturday nearest September 30 each year. The Company’s fiscal year is divided into four quarters of 13 weeks, each beginning on a Sunday and containing two 4-week periods followed by a 5-week period. An additional week is included in the fourth fiscal quarter approximately every five years to realign fiscal quarters with calendar quarters. This occurred last in the fourth quarter of the Company’s fiscal year ended October 3, 2015 and will next reoccur in the fiscal year ended October 3, 2020. References to fiscal 2019 are to the Company’s fiscal year ended September 28, 2019 , references to fiscal 2018 are to the Company’s fiscal year ended September 29, 2018 and references to fiscal 2017 are to the Company’s fiscal year ended September 30, 2017 . Stock split On July 19, 2018, the Company effected a two -for-one stock split of all outstanding shares of the Company’s capital stock, including its common stock and its redeemable convertible preferred stock. All share and per share information presented in the consolidated financial statements have been retroactively adjusted for all periods presented for the effects of the stock split. Use of estimates and judgments The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and judgments that affect the amounts reported and disclosed in the consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates. For revenue recognition, examples of estimates and judgments include: determining the nature and timing of satisfaction of performance obligations, determining the standalone selling price ("SSP") of performance obligations, estimating variable consideration such as sales incentives, and product returns. Additionally, estimates and judgments are made by management for allowances for doubtful accounts, the market value of and demand for inventory, useful lives associated with property and equipment, valuation allowances with respect to deferred tax assets and uncertain tax positions, impairment of long-lived assets, goodwill impairment, warranty, contingencies and valuation and assumptions underlying stock-based compensation and other equity instruments. On an ongoing basis, the Company evaluates its estimates and judgments compared to historical experience and trends that form the basis for making estimates and judgments about the carrying value of assets and liabilities. Comprehensive loss Comprehensive loss consists of two components: net loss and other comprehensive income (loss) . Other comprehensive income (loss) refers to net gains and losses that are recorded as an element of stockholders’ equity (deficit), but are excluded from net loss . The Company’s other comprehensive income (loss) consists of net unrealized gains and losses on foreign currency translation adjustments from those subsidiaries not using the U.S. dollar as their functional currency. Cash and cash equivalents Cash equivalents consist of short-term, highly liquid financial instruments with insignificant interest rate risk that are readily convertible to cash and have maturities of three months or less from the date of purchase. As of September 28, 2019 and September 29, 2018 , cash equivalents consisted of money market funds, which are recorded at fair value. Restricted cash The Company held $0.2 million in restricted cash as of September 28, 2019 and September 29, 2018 , representing security deposits on real estate leases. Accounts receivable Accounts receivable are recorded at the invoiced amount less allowances for doubtful accounts and sales incentives, do not require collateral and do not bear interest. The allowance for doubtful accounts is established through a provision for net bad debt expense which is recorded in general and administrative expense in the consolidated statements of operations and comprehensive loss. The Company determines the adequacy of the allowance for doubtful accounts by evaluating customer accounts receivable balances as well as the customer’s financial condition, credit history and current economic conditions. This estimate is periodically adjusted as a result of the aforementioned process, or when the Company becomes aware of a specific customer’s inability to meet its financial obligations. Concentration of credit risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist principally of cash and cash equivalents and accounts receivable. The Company maintains cash and cash equivalents in several high-quality financial institutions. Cash and cash equivalents held at these banks, including those held in foreign branches of global banks, may exceed the amount of insurance provided on such deposits. These deposits may be redeemed upon demand and management believes that the financial institutions that hold the Company’s cash and cash equivalents are financially sound and, accordingly, minimal credit risk exists with respect to cash. The Company has not experienced any losses in such accounts. As of September 28, 2019 and September 29, 2018 , the Company’s customers that accounted for 10% or more of total accounts receivable, net, were as follows: Accounts receivable, net 2019 2018 Customer A 20 % 31 % Customer B 14 % 13 % Customer C * 11 % Customer E 10 % * * Accounts receivable was less than 10%. The Company’s customers that accounted for 10% or more of total revenue were as follows: Revenue Year Ended 2019 2018 2017 Customer A 16 % 17 % 16 % Customer C 10 % 10 % 12 % Inventories Inventories primarily consist of finished goods and to a lesser extent component parts, which are purchased from contract manufacturers and component suppliers. Inventories are stated at lower of cost and net realizable value on a first-in, first-out basis. The Company assesses the valuation of inventory balances including an assessment to determine potential excess and/or obsolete inventory. The Company may be required to write down the value of inventory if estimates of future demand and market conditions indicate estimated excess or obsolete inventory. For the periods presented, the Company has not experienced significant write-downs. Property and equipment, net Property and equipment are stated at historical cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets as follows: Computer hardware and software 2-3 years Furniture and fixtures 3-5 years Tooling and production line test equipment 2-4 years Leasehold improvements 2-10 years Product displays 1-3 years Costs incurred to improve leased office space are capitalized. Leasehold improvements are amortized on a straight-line basis over the shorter of the term of the lease or the estimated useful life of the improvement. Expenditures for major renewals and improvements that extend the useful lives of property and equipment are capitalized. Maintenance, repair costs and gains or losses associated with disposals are charged to expense as incurred. Product displays are deployed at retail locations. Because the product displays facilitate marketing of the Company’s products within the retail stores, depreciation for product displays is recorded in sales and marketing expenses in the consolidated statements of operations and comprehensive loss. Impairment of long-lived assets The Company evaluates the recoverability of its long-lived assets, primarily comprised of property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company performs impairment testing at the level that represents the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability is measured by comparing the carrying amounts to the expected future undiscounted cash flows attributable to the assets. If it is determined that an asset may not be recoverable, an impairment loss equal to the excess of the asset’s carrying value over its fair value is recorded. Fair value is determined based upon estimated discounted future cash flows. There were no impairment charges identified on the Company’s long-lived assets for each period presented. Product warranties The Company’s products are covered by warranty to be free from defects in material and workmanship for a period of one year , except in the European Union and select other countries where the Company provides a two -year warranty on all its products. At the time of sale, an estimate of future warranty costs is recorded as a component of cost of revenue and a warranty liability is recorded for estimated costs to satisfy the warranty obligation. The Company’s estimate of costs to fulfill its warranty obligations is based on historical experience and expectations of future costs to repair or replace. Legal contingencies If a potential loss from any claim or legal proceeding is considered probable, and the amount can be reasonably estimated, the Company accrues a liability for an estimated loss. Legal fees are expensed as incurred and included in general and administrative expenses in the consolidated statements of operations and comprehensive loss. See Note 11 for additional information regarding legal contingencies. Treasury stock The Company accounts for treasury stock acquisitions using the cost method. The Company accounts for the retirement of treasury stock by deducting its par value from common stock and reflecting any excess of cost over par value as a deduction from additional paid-in capital on the consolidated balance sheets. Fair value accounting Assets and liabilities recorded at fair value on the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level Input Input Definition Level 1 Quoted prices for identical assets or liabilities in active markets at the measurement date. Level 2 Inputs, other than quoted prices included in Level 1, such as quoted prices for similar assets or liabilities, in active markets or other inputs that are observable or can be corroborated with market data at the measurement date. Level 3 Unobservable inputs that reflect management's best estimate of what market participants would use in pricing the asset or liability at the measurement date. Foreign currency Certain of the Company’s wholly owned subsidiaries have non-U.S. dollar functional currencies. The Company translates assets and liabilities of non-U.S. dollar functional currency subsidiaries into U.S. dollars using exchange rates in effect at the end of each period and stockholders’ equity at historical rates. Revenue and expenses for these subsidiaries are translated using rates that approximate those in effect during the period. Gains and losses from translation are recognized in foreign currency translation included in accumulated other comprehensive loss . The Company remeasures monetary assets or liabilities denominated in currencies other than the functional currency using exchange rates prevailing on the balance sheet date, and non-monetary assets and liabilities at historical rates. Foreign currency remeasurement and transaction gains and losses are included in other income (expense), net. Foreign currency remeasurement and transaction gains (losses) are recorded in other income (expense), net and were $(8.6) million , $(1.2) million and $3.2 million for fiscal 2019 , 2018 and 2017 , respectively. Revenue recognition Revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. The Company generally enters into contracts that include a combination of products and services. Revenue is allocated to distinct performance obligations and is recognized net of allowances for returns, discounts, sales incentives and any taxes collected from customers, which are subsequently remitted to governmental authorities. Shipping and handling costs associated with outbound freight after control over a product has transferred to a customer are accounted for as a fulfillment cost and are included in cost of revenue. As of September 28, 2019 and September 29, 2018 , the Company did not have any material assets related to incremental costs to obtain or fulfill customer contracts. In the prior year, the Company adopted ASC 606 using the full retrospective transition method which resulted in an acceleration of revenue and related costs of revenue and most significantly, a reduction in deferred costs and revenue and deferred revenue at each balance sheet date. Nature of products and services Product revenue includes sales of wireless speakers, home theater speakers and components, which include software that enables the Company’s products to operate over a customer’s wireless network, as well as connect to various third-party services, including music and voice. The Company also generates a small portion of revenue from other revenue sources such as sales of module units and Sonos and third-party accessories, which include speaker stands and wall mounts. Module revenue is comprised of hardware and embedded software that is integrated into final products that are manufactured and sold by the Company's partners. Software primarily consists of firmware embedded in the products and the Sonos app, which is software that can be downloaded to consumer devices at no charge, with or without the purchase of one of the Company’s products. Products and related software are accounted for as a single performance obligation and all intended functionality is available to the customer upon purchase. The revenue allocated to the products and related software is the substantial portion of the total sale price. Product revenue is recognized at the point in time when control is transferred, which is either upon shipment or upon delivery to the customer, depending on delivery terms. Service revenue includes revenue allocated to (i) unspecified software upgrades and (ii) cloud-based services that enable products to access third-party music and voice assistant platforms, which are each distinct performance obligations and are provided to customers at no additional charge. Unspecified software upgrades are provided on a when-and-if-available basis and have historically included updates and enhancements such as bug fixes, feature enhancements and updates to the ability to connect to third-party music or voice assistant platforms. Service revenue is recognized ratably over the estimated service period. Significant judgments The Company’s contracts with customers generally contain promises to transfer products and services as described above. Determining whether products and services are considered distinct performance obligations that should be accounted for separately requires significant judgment. Judgment is required to determine the SSP for each distinct performance obligation. The Company estimates SSP for items that are not sold separately, which include the products and related software, unspecified software upgrades and cloud-based services, using information that may include competitive pricing information, where available, as well as analyses of the cost of providing the products or services plus a reasonable margin. In developing SSP estimates, the Company also considers the nature of the products and services and the expected level of future services. Determining the revenue recognition period for unspecified software upgrades and cloud-based services also requires judgment. The Company recognizes revenue attributable to these performance obligations ratably over the best estimate of the period that the customer is expected to receive the services. In developing the estimated period of providing future services, the Company considers past history, plans to continue to provide services, including plans to continue to support updates and enhancements to prior versions of the Company’s products, expected technological developments, obsolescence, competition and other factors. The estimated service period may change in the future in response to competition, technology developments and the Company’s business strategy. The Company offers sales incentives through various programs consisting primarily of discounts, cooperative advertising and market development fund programs. The Company records cooperative advertising and market development fund programs with customers as a reduction to revenue unless it receives a distinct benefit in exchange for credits claimed by the customer and can reasonably estimate the fair value of the benefit received, in which case the Company records it as an expense. The Company recognizes a liability or a reduction to accounts receivable, and reduces revenue based on the estimated amount of sales incentives that will be claimed by customers. Estimates for sales incentives are developed using the most likely amount and are included in the transaction price to the extent that a significant reversal of revenue would not result once the uncertainty is resolved. In developing its estimate, the Company also considers the susceptibility of the incentive to outside influences, the length of time until the uncertainty is resolved and the Company’s experience with similar contracts. Reductions in revenue related to discounts are allocated to products and services on a relative basis based on their respective SSP. Judgment is required to determine the timing and amount of recognition of marketing funds which the Company estimates based on past practice of providing similar funds. The Company accepts returns from direct customers and from certain resellers. To establish an estimate for returns, the Company uses the expected value method by considering a portfolio of contracts with similar characteristics to calculate the historical returns rate. When determining the expected value of returns, the Company considers future business initiatives and relevant anticipated future events. Supplier concentration The Company relies on third parties for the supply and manufacture of its products, 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 or satisfactorily deliver its products to customers on time, if at all. During fiscal 2019 , 2018 and 2017 , approximately 83% , 98% and 99% , respectively, of the Company’s finished goods purchased during each year were from one vendor. Deferred revenue and payment terms The Company invoices each order upon hardware shipment or delivery and recognizes revenue for each distinct performance obligation when transfer of control has occurred, which in the case of services, may extend over several reporting periods. Amounts invoiced in advance of revenue recognition are recorded as deferred revenue on the consolidated balance sheets. Deferred revenue primarily relates to revenue allocated to unspecified software upgrades and platform services. The Company classifies deferred revenue as noncurrent if amounts are expected to be recognized as revenue after more than one year from the balance sheet date. Payment terms Payment terms and conditions vary among the Company’s distribution channels although terms generally include a requirement of payment within 30 days of product shipment. Sales directly to customers from the Company’s website are paid at the time of product shipment. Prior to providing payment terms to customers, an evaluation of the customer’s credit risk is performed. Contractual allowances are an offset to accounts receivable. Research and development Research and development expenses consist primarily of personnel-related expenses, consulting and outside professional service costs, tooling and prototype materials and overhead costs. Substantially all of the Company’s research and development expenses are related to developing new products and services and improving existing products and services. To date, software development costs have been expensed as incurred because the period between achieving technological feasibility and the release of the software has been short and development costs qualifying for capitalization have been insignificant. Advertising costs Advertising costs are expensed as incurred and included in sales and marketing expenses. Advertising expenses were $48.8 million , $50.2 million and $72.2 million for fiscal 2019 , 2018 and 2017 , respectively. Stock-based compensation The Company measures stock-based compensation cost at fair value on the date of grant. Compensation cost for stock options is recognized, on a straight-line basis, as an expense over the period of vesting as the employee performs the related services, net of estimated forfeitures. The Company estimates the fair value of stock option awards using the Black-Scholes option-pricing model. The fair value of restricted stock units ("RSUs") is based on the Company's closing stock price on the trading day immediately preceding the date of grant and for stock options with graded vesting are recognized, on a straight-line basis, as an expense over the period of vesting as the employee performs the related services, net of estimated forfeitures. The Company estimates forfeitures based on expected future terminations and will revise rates, as necessary, in subsequent periods if actual forfeitures differ from initial estimates. Retirement Plans The Company has a defined contribution 401(k) plan (the "401(k) Plan") for the Company’s U.S.-based employees, as well as various benefit plans, principally defined contribution plans, for its international employees. Eligible U.S. employees may contribute up to 100% of their annual compensation under the 401(k) plan, but are limited to the maximum annual dollar amount allowable under the Internal Revenue Code of 1986, as amended (the "Code"). In the second quarter of fiscal 2019, the Company began making matching contributions towards the 401(k) Plan, as well as towards the international defined contribution plans. Income taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company records a valuation allowance to the extent that its deferred tax assets are not more likely than not to be realized. In making such a determination, all available positive and negative evidence is considered, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies and results of recent operations. If the Company determines that it would be able to realize its deferred tax assets in the future in excess of their net recorded amount, the Company would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions in accordance with a two-step process whereby (i) the Company determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more likely than not recognition threshold, the Company recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company includes interest and penalties related to unrecognized tax benefits within the provision for income taxes in the consolidated statements of operations and comprehensive loss. The Company has not incurred any interest or penalties related to unrecognized tax benefits in any of the periods presented. The Company’s provision for (benefit from) income taxes, deferred tax assets and liabilities and liabilities for unrecognized tax benefits involves the use of estimates, assumptions and judgments. Although the Company believes its estimates, assumptions and judgments to be reasonable, any changes in tax law or its interpretation of tax laws and the resolutions of potential tax audits could significantly impact the amounts provided for income taxes in the Company’s consolidated financial statements. Actual future operating results and the underlying amount and type of income could differ materially from the Company’s estimates, assumptions and judgments thereby impacting the Company’s financial position and results of operations. Segment information The Company operates as one operating segment as it only reports aggregate financial information on a consolidated basis, accompanied by disaggregated information about revenue by geographic region and product category to its Chief Executive Officer, who is the Company’s chief operating decision maker. Leases The substantial majority of the Company’s leases are for its office spaces and facilities, which are accounted for as operating leases. For leases that contain rent escalation or rent concession provisions, the Company recognizes rent on a straight-line basis over the term of the lease. The Company does not assume renewals in its determination of the lease term unless the renewals are deemed to be reasonably assured at inception. Tenant improvement allowances received from landlords are recorded as a credit to deferred rent, reported as a liability on the consolidated balance sheets and amortized on a straight-line basis over the lease term as a reduction to rent expense in the consolidated statements of operations and comprehensive loss. Recently adopted accounting pronouncements Stock-based compensation In June 2018, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting , which aligns the accounting for share-based payment awards issued to nonemployees with the guidance applicable to grants to employees. Under this new standard, equity-classified share-based payment awards issued to nonemployees will be measured on the grant date, instead of the current requirement to remeasure the awards through the performance completion date. Further, compensation cost for awards with performance conditions will be recognized when it is probable the conditions will be achieved, rather than upon actual achievement of the conditions. In the second quarter of fiscal 2019, the Company early adopted the standard using the prospective approach. There was no cumulative effect entry needed to adjust the opening retained earnings balance upon adoption. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. Statement of cash flows In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash , which enhances and clarifies the classification and presentation of restricted cash in the statement of cash flows. In the first quarter of fiscal 2019, the Company adopted this standard retrospectively to all periods presented. The Company now includes restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling beginning and ending amounts shown on the statement of cash flows. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, which reduces diversity in practice in how certain transactions are classified in the statement of cash flows. In the first quarter of fiscal 2019, the Company retrospectively adopted this standard to all periods presented. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. Income taxes In October 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other than Inventory . This guidance removes the prohibition in Accounting Standards Codification ("ASC") Topic 740, Income Taxes, against the immediate recognition of the current and deferred income tax effects of intra-entity transfers of assets other than inventory. ASU 2016-16 is intended to reduce the complexity of U.S. GAAP and diversity in practice related to the tax consequences of certain types of intra-entity asset transfers, particularly those involving intellectual property. In the first quarter of fiscal 2019, the Company adopted this standard on a modified retrospective basis. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. Recent accounting pronouncements pending adoption In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) , and other subsequent amendments, collectively referred to as Topic 842, which modifies lease accounting in order to increase transparency and comparability among entities. The standard requires lessees to recognize on the balance sheet, right-of-use assets and lease liabilities for the rights and obligations created by leases. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted improvements, which provides an alternative transition method that entities can elect when adopting this standard. The Company plans to adopt the new standard effective September 29, 2019, using the optional transition method, recognizing a cumulative-effect adjustment to its balance of accumulated deficit at September 29, 2019 without restating comparative periods presented. The Company’s leases primarily include real estate leases and automobile leases. In adopting the new guidance, the Company will elect, amongst other practical expediencies, not to reassess (1) whether any expired or existing contracts contain leases under the new definition of a lease; (2) the lease classification for any expired or existing leases; and (3) whether previously capitalized initial direct costs would qualify for capitalization under Topic 842. Also, for leases with lease terms less than twelve months, an entity is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. The Company intends to make this election for all classes of assets. Upon adoption of this standard on September 29, 2019, the Company expects an increase in both total assets and total liabilities of approximately $60.0 million to $65.0 million. The Company does not believe that the adoption of the standard will have a material impact on the Company’s consolidated statements of operations and comprehensive loss or to the consolidated statements of cash flows. The Company continues to finalize the implementation of new processes and the assessment of the impact of this adoption on its consolidated financial statements; therefore, the preliminary estimated impacts disclosed can change and the final impact will be known once the adoption is completed during the

Fair value measurements

Fair value measurements	12 Months Ended
	Sep. 28, 2019
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements The carrying values of the Company’s financial instruments, including accounts receivable and accounts payable, approximate their fair values due to the short period of time to maturity or repayment. The carrying values of the Company’s long-term debt approximate their fair values as of September 28, 2019 and September 29, 2018 as the debt carries a variable rate or market rates that approximate those currently available to the Company. The following table summarizes fair value measurements by level for the assets measured at fair value on a recurring basis as of September 28, 2019 and September 29, 2018 : 2019 (In thousands) Level 1 Level 2 Level 3 Total Assets: Money market funds (cash equivalents) $ 267,806 $ — $ — $ 267,806 2018 (In thousands) Level 1 Level 2 Level 3 Total Assets: Money market funds (cash equivalents) $ 140,588 $ — $ — $ 140,588

Revenue and geographic informat

Revenue and geographic information	12 Months Ended
	Sep. 28, 2019
Revenue from Contract with Customer [Abstract]
Revenue and geographic information	Revenue and geographic information Disaggregation of revenue Revenue by geographical region, based on ship-to address, is as follows: 2019 2018 2017 (In thousands) Americas $ 678,224 $ 603,450 $ 496,668 Europe, Middle East and Africa ("EMEA") 484,785 478,518 442,081 Asia Pacific ("APAC") 97,814 55,040 53,777 Total revenue $ 1,260,823 $ 1,137,008 $ 992,526 Revenue from external customers is attributed to individual countries based on ship-to address. Revenue by significant countries is as follows: 2019 2018 2017 (In thousands) United States $ 630,012 $ 554,896 $ 449,261 Germany 124,385 121,546 111,065 United Kingdom 112,708 114,790 110,695 Other countries 393,718 345,776 321,505 Total revenue $ 1,260,823 $ 1,137,008 $ 992,526 Revenue by major product category is as follows: 2019 2018 2017 (In thousands) Wireless speakers $ 518,821 $ 546,649 $ 480,977 Home theater speakers 489,602 418,416 348,899 Components 188,861 150,436 151,965 Other 63,539 21,507 10,685 Total revenue $ 1,260,823 $ 1,137,008 $ 992,526 Revenue by product categories includes the applicable service revenue attributable to each product category. Property and equipment, net by country as of September 28, 2019 and September 29, 2018 were as follows: 2019 2018 (In thousands) United States $ 48,370 $ 48,441 China 16,539 18,729 Other countries 13,230 18,201 Property and equipment, net $ 78,139 $ 85,371

Balance sheet components

Balance sheet components	12 Months Ended
	Sep. 28, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance sheet components	Balance sheet components The following tables show the Company’s balance sheet component details as of September 28, 2019 and September 29, 2018 . Accounts receivable allowances The following table summarizes changes in the allowance for doubtful accounts for fiscal 2019 , 2018 and 2017 : 2019 2018 2017 (In thousands) Beginning balance $ 872 $ 804 $ 726 Increases 1,034 635 449 Write-offs (651 ) (567 ) (371 ) Ending balance $ 1,255 $ 872 $ 804 The following table summarizes the changes in the allowance for sales incentives for fiscal 2019 , 2018 and 2017 : 2019 2018 2017 (In thousands) Beginning balance $ 11,754 $ 11,195 $ 8,913 Charged to revenue 87,703 90,246 65,879 Utilization of sales incentive allowance (79,406 ) (89,687 ) (63,597 ) Ending balance $ 20,051 $ 11,754 $ 11,195 Inventories Inventories, net, consist of the following: 2019 2018 (In thousands) Finished goods $ 207,723 $ 176,181 Components 12,061 17,012 Inventories $ 219,784 $ 193,193 Property and equipment, net Property and equipment, net consist of the following: 2019 2018 (In thousands) Computer hardware and software $ 47,775 $ 46,385 Furniture and fixtures 9,594 9,696 Tooling and production line test equipment 54,536 47,297 Leasehold improvements 58,944 53,962 Product displays 45,672 40,265 Total property and equipment 216,521 197,605 Accumulated depreciation and amortization (138,382 ) (112,234 ) Property and equipment, net $ 78,139 $ 85,371 Depreciation expense was $36.4 million , $39.4 million and $35.0 million for fiscal 2019 , 2018 and 2017 , respectively. During fiscal 2019 , 2018 and 2017 , the Company disposed of gross fixed assets of $10.2 million , $35.8 million and $11.5 million , with accumulated depreciation of $9.3 million , $35.6 million and $11.2 million , respectively. Disposals of fixed assets were recorded in operating expenses in the consolidated statements of operations and comprehensive loss and resulted in losses of $0.8 million , $0.2 million and $0.2 million for fiscal 2019 , 2018 and 2017 , respectively. Accrued expenses Accrued expenses consisted of the following: 2019 2018 (In thousands) Accrued advertising and marketing $ 25,662 $ 11,613 Accrued taxes 4,388 4,175 Accrued inventory 6,494 4,179 Accrued manufacturing, logistics and product development 14,783 8,290 Accrued general and administrative 12,455 3,322 Other accrued payables 6,074 7,108 Total accrued expenses $ 69,856 $ 38,687 The following table summarizes the changes in the deferred revenue balances: 2019 2018 2017 (In thousands) Deferred revenue, beginning of period $ 50,967 $ 45,567 $ 36,160 Recognition of revenue included in beginning of period deferred revenue (11,934 ) (10,627 ) (6,878 ) Revenue deferred, net of revenue recognized on contracts in the respective period 17,416 16,027 16,285 Deferred revenue, end of period $ 56,449 $ 50,967 $ 45,567 The Company expected the following recognition of deferred revenue as of September 28, 2019 : For the fiscal years ending (In thousands) 2020 2021 2022 2023 2024 and Beyond Total Revenue expected to be recognized $ 13,654 $ 12,143 $ 10,297 $ 8,369 $ 11,986 $ 56,449 Other current liabilities Other current liabilities consist of the following: September 28, September 29, (In thousands) Reserve for returns $ 12,110 $ 5,005 Product warranty liability 3,254 2,450 Other 2,184 3,403 Total other current liabilities $ 17,548 $ 10,858 The following table presents the changes in the Company’s warranty liability for the fiscal years ended September 28, 2019 and September 29, 2018 : September 28, September 29, (In thousands) Warranty liability, beginning of period $ 2,450 $ 2,437 Provision for warranties issued during the period 12,795 10,678 Settlements of warranty claims during the period (11,991 ) (10,665 ) Warranty liability, end of period $ 3,254 $ 2,450

Debt

Debt	12 Months Ended
	Sep. 28, 2019
Debt Disclosure [Abstract]
Debt	Debt The Company's debt obligations consist of the Secured Credit Facility with J.P. Morgan Chase Bank, N.A. (the“Credit Facility”) and the J.P. Morgan Chase Bank, N.A. Secured Term Loan (the "Term Loan"). The Company’s short and long term debt as of September 28, 2019 and September 29, 2018 is as follows: 2019 2018 Rate Balance Rate Balance (In thousands) Term Loan (1) 4.6 % $ 33,333 4.8 % $ 40,000 Unamortized debt issuance costs (2) (160 ) (236 ) Total indebtedness 33,173 39,764 Less short term portion (8,333 ) (6,667 ) Long term debt $ 24,840 $ 33,097 (1) Bears interest at a variable rate equal to an adjusted LIBOR plus 2.25% and is payable quarterly. Due in October 2021, with quarterly principal payments beginning in July 2019. (2) Debt issuance costs are recorded as a debt discount and charged to interest expense over the term of the agreement. The Credit Facility allows the Company to borrow up to $80.0 million restricted to the value of the borrowing base which is based on the value of inventory and accounts receivable and is subject to quarterly redetermination. The Credit Facility matures in October 2021 and may be drawn as Commercial Bank Floating Rate Loans (at the higher of the prime rate or adjusted LIBOR plus 2.50% ) or Eurocurrency Loans (at LIBOR plus an applicable margin). As of September 28, 2019 and September 29, 2018 , the Company did not have any outstanding borrowings and $4.5 million and $4.5 million , respectively, in undrawn letters of credit that reduce the availability under the Credit Facility. Debt obligations under the Credit Facility and the Term Loan require the Company to maintain a consolidated fixed charge ratio of at least 1.0 , restrict distribution of dividends unless certain conditions are met, such as having a fixed charge ratio of at least 1.15 , and require financial statement reporting and delivery of borrowing base certificates. As of September 28, 2019 and September 29, 2018 , the Company was in compliance with all financial covenants. The Credit Facility and the Term Loan are collateralized by eligible inventory and accounts receivable of the Company, as well as the Company's intellectual property including patents and trademarks.

Stockholders' equity

Stockholders' equity	12 Months Ended
	Sep. 28, 2019
Equity [Abstract]
Stockholders' equity	Stockholders' equity Redeemable convertible preferred stock Upon the closing of the IPO, all outstanding shares of the Company's redeemable convertible preferred stock automatically converted into 32,482,590 shares of common stock on a one -for-one basis. Additionally, upon completion of the IPO, the Company's authorized capital stock consisted of 500,000,000 shares of common stock, $0.001 par value per share and 10,000,000 shares of "blank check" preferred stock, $0.001 par value per share. Share repurchase program On September 3, 2019, the Company announced that its Board of Directors has authorized a common stock repurchase program of up to $50.0 million . No shares of the Company's stock were repurchased under this program during fiscal 2019. The Company withholds shares of common stock from certain employees in connection with the vesting of restricted stock unit awards issued to such employees to satisfy applicable tax withholding requirements. Such withheld shares are treated as common stock repurchases in our consolidated financial statements as they reduce the number of shares that would have been issued upon vesting. Repurchases associated with tax withholdings were not material during fiscal 2019.

Stock-based compensation

Stock-based compensation	12 Months Ended
	Sep. 28, 2019
Share-based Payment Arrangement [Abstract]
Stock-based compensation	Stock-based compensation 2018 Equity Incentive Plan In July 2018, the Board adopted the 2018 Equity Incentive Plan (the “2018 Plan”), which became effective in connection with the IPO, and ceased granting awards under the 2003 Stock Plan (the "2003 Plan"). The Company initially reserved 21,839,258 shares of its common stock for issuance under the 2018 Plan, which included any remaining shares available for issuance under the 2003 Plan on the effective date of the 2018 Plan. The number of shares reserved for issuance under the 2018 Plan will also be increased by expired or forfeited shares under the 2003 Plan, or shares issued under the 2003 Plan which are repurchased at their original issue price. Shares subject to awards under the 2003 Plan that are used to pay the exercise price of an option or withheld to satisfy the tax withholding obligations related to any award will not become available for future grant or sale under the 2018 Plan. The number of shares reserved for issuance under the 2018 Plan will increase automatically on January 1 of each year beginning in 2019 and continuing through 2028 by a number of shares of common stock equal to the lesser of (x) 5% of the total outstanding shares of the Company’s common stock and common stock equivalents as of the immediately preceding December 31 (rounded to the nearest whole share) and (y) a number of shares determined by the Board. As of September 28, 2019 , there were 25,280,393 shares reserved for future issuance under the 2018 Plan. Stock options Pursuant to the 2018 Plan, the Company issues stock options to employees. The fair value of the stock options is based on the Company’s closing stock price on the trading day immediately prior to the date of grant. The option price, number of shares and grant date are determined at the discretion of the Board. For so long as the optionholder performs services for the Company, the options generally vest over 48 months , with cliff vesting after one year and generally vest on a monthly or quarterly basis thereafter, and are exercisable for a period not to exceed ten years from the date of grant. The summary of the Company’s stock option activity is as follows: Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in thousands) Outstanding at September 29, 2018 48,504,182 $ 10.33 6.6 $ 276,959 Granted 1,714,328 13.34 Exercised (7,925,897 ) 3.98 Forfeited (5,137,045 ) 13.48 Outstanding at September 28, 2019 37,155,568 $ 11.39 6.3 $ 94,288 At September 28, 2019 Options exercisable 26,436,074 $ 10.23 5.5 $ 92,281 Options vested and expected to vest 35,606,324 $ 11.25 6.2 $ 93,836 During fiscal 2019 , 2018 and 2017 , the Company granted options with a fair value of $ 8.4 million, $ 50.2 million and $ 39.4 million, respectively, with a weighted-average grant date fair value of $ 4.91 , $ 5.39 and $ 4.84 per share, respectively. Options vested in 2019 , 2018 and 2017 , respectively, have a fair value of $34.3 million , $38.3 million , and $34.8 million . The total intrinsic value of stock options exercised was $ 61.1 million, $ 31.3 million and $ 42.0 million for fiscal 2019 , 2018 and 2017 , respectively. As of September 28, 2019 and September 29, 2018 , the Company had $ 43.9 million and $ 71.5 million, respectively, of unrecognized stock-based compensation cost, which is expected to be recognized over a weighted-average period of 2.0 years and 2.6 years, respectively. The Company’s policy for issuing stock upon stock option exercise is to issue new common stock. The Company uses the Black- Scholes option pricing model to estimate the fair value of stock options. This model requires the input of highly subjective assumptions including the expected term of the option, expected stock price volatility and expected dividends. If any of the assumptions used in the Black-Scholes model changes significantly, stock-based compensation expense may differ materially in the future from that recorded in the current period. The fair value of options at the date of grant was estimated with the following weighted-average assumptions: 2019 2018 2017 Expected term (years) 6.51 6.25 6.25 Risk-free interest rate 2.67 % 2.73 % 1.95 % Expected volatility 30.7 % 30.2 % 32.4 % Expected dividend yield — % — % — % Expected term The expected term represents the period over which the Company anticipates stock-based awards to be outstanding. The Company does not have sufficient historical exercise data to provide a reasonable basis upon which to estimate expected term. As a result, the Company elected the simplified method, which is the average of the options’ vesting and contractual terms. Risk-free interest rate The risk-free interest rate is based on the U.S. Treasury yield curve in effect at the time of grant for the expected term of the option. Expected share price volatility The Company’s computation of expected volatility is based on the historical volatility of selected comparable publicly traded companies over a period equal to the expected term of the option. Expected dividend yield The Company used a zero-dividend yield, as the Company has never paid dividends and does not plan to pay dividends in the near future. Fair value of common stock Prior to the IPO, in accordance with the American Institute of Certified Public Accountants Accounting and Valuation Guide, Valuation of Privately-Held Company Equity Securities Issued as Compensation , the Board exercised reasonable judgment and considered numerous objective and subjective factors to determine the best estimate of fair value of the Company’s common stock, including but not limited to the prices at which the Company sold shares of its common stock to outside investors in arm’s-length transactions; independent third-party valuations of the Company’s common stock; the rights, preferences and privileges of redeemable convertible preferred stock relative to those of common stock; the Company’s operating results, financial position and capital resources; and additional relevant economic information. Subsequent to the Company's IPO, the Company began using the market closing price for its common stock as reported on The Nasdaq Global Select Market. Restricted stock units Pursuant to the 2018 Plan, the Company issues RSUs to employees. The fair value of RSUs is based on the Company's closing stock price on the trading day immediately preceding the date of grant. RSUs typically have an initial annual cliff vest and then vest quarterly over the service period, which is generally four years . The summary of the Company’s unvested RSU activity is as follows: Number of Units Weighted Average Grant Date Fair Value Aggregate Intrinsic Value (in thousands) Outstanding at September 29, 2018 — $ — $ — Granted 7,915,980 Exercised (829,270 ) Forfeited (369,924 ) Expired — Outstanding at September 28, 2019 6,716,786 $ 11.4 $ 90,744 At September 28, 2019 Units expected to vest 5,207,691 $ 11.4 $ 70,356 As of September 28, 2019 , the Company had $55.6 million of unrecognized stock-based compensation expense related to their RSUs, which is expected to be recognized over a weighted-average period of 3.4 years. Total stock-based compensation expense by function category was as follows: 2019 2018 2017 (In thousands) Cost of revenue $ 985 $ 198 $ 240 Research and development 17,643 13,960 13,605 Sales and marketing 12,965 15,885 15,086 General and administrative 14,982 8,602 7,619 Total stock-based compensation expense $ 46,575 $ 38,645 $ 36,550

Income taxes

Income taxes	12 Months Ended
	Sep. 28, 2019
Income Tax Disclosure [Abstract]
Income taxes	Income taxes The Company’s loss before provision for (benefit from) income taxes for fiscal 2019 , 2018 and 2017 were as follows: 2019 2018 2017 (In thousands) Domestic $ (858 ) $ 2,803 $ (25,005 ) Foreign (218 ) (17,351 ) 8,497 Loss before provision for (benefit from) income taxes $ (1,076 ) $ (14,548 ) $ (16,508 ) Components of the provision for (benefit from) income taxes consisted of the following: 2019 2018 2017 (In thousands) Current: U.S. Federal $ 1,366 $ — $ — U.S. State 1,132 177 62 Foreign 1,463 816 (3,791 ) Total current 3,961 993 (3,729 ) Deferred: U.S. Federal — (168 ) — U.S. State — — — Foreign (271 ) 231 1,438 Total deferred (271 ) 63 1,438 Provision for (benefit from) income taxes $ 3,690 $ 1,056 $ (2,291 ) Components of the Company’s net deferred income tax assets (liabilities) are as follows: 2019 2018 (In thousands) Deferred tax assets Accrued expenses and reserves $ 12,582 $ 5,639 Deferred revenue 11,185 10,317 U.S. net operating loss carryforwards 15,112 18,385 Foreign net operating loss carryforwards 3,414 5,625 Tax credit carryforwards 43,411 22,969 Stock-based compensation 10,368 7,237 Amortization 4,131 3,237 Depreciation 672 — Other 453 427 Total deferred tax assets 101,328 73,836 Valuation allowance (95,088 ) (72,380 ) Deferred tax assets, net of valuation allowance 6,240 1,456 Deferred tax liabilities Tax accounting method change (5,086 ) — Depreciation — (515 ) Total deferred tax liabilities (5,086 ) (515 ) Net deferred tax assets $ 1,154 $ 941 After considering all available positive and negative evidence, the Company has determined it is more likely than not that deferred tax assets in the United States and the Netherlands will not be realized and that a full valuation allowance is required. The Company has maintained a full valuation allowance on its U.S. deferred tax assets due to its history of U.S. operating losses. It is possible that within the next 12 months there may be sufficient positive evidence to release a significant portion of the valuation allowance. Release of the U.S. valuation allowance would result in the establishment of certain deferred tax assets and a benefit to income tax expense for the period the release is recorded, which could have a material impact on net earnings. The exact timing and amount of the valuation allowance release are subject to change based on the level of profitability achieved. The Company has deferred tax assets in other foreign jurisdictions which it determined are more likely than not to be fully realized. As of September 28, 2019 , the Company had gross federal and post-apportionment state net operating loss carryforwards of $60.6 million and $36.2 million , respectively, available to reduce future taxable income. The earliest federal and state net operating loss carryforwards expire in varying amounts beginning in 2035 and 2027 , respectively. As of September 28, 2019 , the Company had gross foreign net operating loss carryforwards of $16.1 million , of which $1.4 million have an indefinite life and $14.7 million will expire in 2027 . The Company also has gross federal and state research and development tax credits carryforwards of $33.8 million and $25.9 million , respectively. The federal research credits will begin to expire in the year 2025 , and the state research credits will begin to expire in the year 2024 . Because of the change of ownership provisions of Sections 382 and 383 of the Code, use of a portion of the Company’s domestic net operating losses and tax credit carryforwards may be limited in future periods depending upon future changes in ownership. Further, a portion of the carryforwards may expire before being applied to reduce future income tax liabilities if sufficient taxable income is not generated in future periods. The following table summarizes changes in the valuation allowance for fiscal 2019 , 2018 and 2017 : (In thousands) 2019 2018 2017 Beginning balance $ 72,380 $ 94,956 $ 95,882 Increase (decrease) during the period 22,708 (22,576 ) (926 ) Ending balance $ 95,088 $ 72,380 $ 94,956 Reconciliation of U.S. statutory federal income taxes to the Company’s provision for (benefit from) income taxes is as follows: (In thousands) 2019 2018 2017 U.S. federal income taxes at statutory rate $ (226 ) $ (3,570 ) $ (5,778 ) U.S. state and local income taxes (9,315 ) (1,441 ) (2,454 ) Foreign income tax rate differential 129 (53 ) (1,101 ) Dutch tax settlement — — 7,361 Stock-based compensation (2,399 ) 4,025 1,503 Federal research tax credits (8,418 ) (4,333 ) (2,978 ) Unrecognized federal tax benefits (2,806 ) 1,990 1,191 Change in tax rate 1,161 25,725 — Net Impact of GILTI 239 — — BEAT 781 — — Other 822 259 1,197 Change in valuation allowance 23,722 (21,546 ) (1,232 ) Provision for (benefit from) income taxes $ 3,690 $ 1,056 $ (2,291 ) In January 2017, the Company entered into a unilateral Advance Pricing Agreement (the "APA") with the Dutch Tax Administration. The APA establishes an intercompany licensing arrangement whereby the operating profit or loss, as determined under U.S. GAAP, of Sonos Europe B.V. and Sonos, Inc. will be allocated between the two companies based on relative contribution to the development of marketing and technology intangibles. The APA has a five -year term that commenced on October 2, 2016 and ends on September 30, 2021. Change in unrecognized tax benefits as a result of uncertain tax positions are as follows: 2019 2018 (In thousands) Beginning balance $ 17,794 $ 13,780 Increase (decrease) - tax positions in prior periods (8,226 ) 636 Increase (decrease) - tax positions in current periods 2,959 3,378 Ending balance $ 12,527 $ 17,794 The Company does not anticipate changes to unrecognized benefits within the next 12 months that would result in a material change to the Company’s financial position. The Company conducts business in a number of tax jurisdictions and, as such, is required to file income tax returns in multiple jurisdictions globally. U.S. federal income tax returns for the 2015 tax year and earlier are no longer subject to examination by the U.S. Internal Revenue Service (the "IRS"). All net operating losses and tax credits generated to date are subject to adjustment for U.S. federal and state purposes. The Company recognizes interest and penalties, if any, related to uncertain tax positions in income tax expense. There was no accrued interest or penalties as of September 28, 2019 and September 29, 2018 . As of September 28, 2019 , no tax provision has been made for $5.9 million of undistributed earnings of certain of the Company’s subsidiaries as these earnings are considered indefinitely reinvested. If, in the future, the Company decides to repatriate the undistributed earnings from these subsidiaries in the form of dividends or otherwise, the Company could be subject to withholding taxes payable at that time. The amount of withholding tax liability is dependent on circumstances existing if and when a remittance occurs but could be reasonably estimated to be $0.5 million .

Net loss per share attributable

Net loss per share attributable to common stockholders	12 Months Ended
	Sep. 28, 2019
Earnings Per Share [Abstract]
Net loss per share attributable to common stockholders	Net loss per share attributable to common stockholders Basic and diluted net loss per share attributable to common stockholders is presented in conformity with the two-class method required for participating securities. The Company considers its redeemable convertible preferred stock to be participating securities as the holders of redeemable convertible preferred stock were entitled to receive noncumulative dividends in the event that a dividend was paid on common stock. Upon the closing of the IPO, all outstanding shares of the Company’s redeemable convertible preferred stock automatically converted into 32,482,590 shares of common stock on a one -for-one basis. Basic net loss attributable to common stockholders per share is calculated by dividing net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding less shares subject to repurchase. Diluted net loss per share attributable to common stockholders adjusts the basic net loss per share attributable to common stockholders and the weighted-average number of shares of common stock outstanding for the potentially dilutive impact of stock options and RSUs, using the treasury stock method, and convertible preferred stock using the as-if-converted method. The following table sets forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders: 2019 2018 2017 (In thousands, except share and per share data) Numerator: Net loss attributable to common stockholders - basic and diluted $ (4,766 ) $ (15,604 ) $ (14,217 ) Denominator: Weighted-average shares of common stock - basic and diluted 103,783,006 65,706,215 56,314,546 Net loss per share attributable to common stockholders: Net loss per share attributable to common stockholders - basic and diluted $ (0.05 ) $ (0.24 ) $ (0.25 ) The following potentially dilutive shares as of the end of each period presented were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive: 2019 2018 2017 Stock options to purchase common stock 42,300,183 48,504,182 45,817,252 RSUs 4,147,463 — — Convertible preferred stock — — 32,482,590 Shares subject to repurchase — — 53,892 Total 46,447,646 48,504,182 78,353,734

Commitments and contingencies

Commitments and contingencies	12 Months Ended
	Sep. 28, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and contingencies Operating leases The Company entered into various non-cancelable operating lease agreements, which are generally for offices and facilities as well for auto leases. The Company’s main offices are leased in California, Massachusetts and the Netherlands with additional sales and operations offices around the world. These facilities operate under leases with initial terms ranging from one to ten years and expire at various dates through 2025. Rent expense during the years ended September 28, 2019 , September 29, 2018 and September 30, 2017 was $ 13.7 million, and $14.5 million and $ 13.5 million, respectively. Inventory The Company enters into various inventory-related purchase agreements with suppliers. Under these agreements, 100% of orders are cancelable by giving sufficient notice prior to the expected shipment date. The following table presents noncancelable payments due by the Company as of September 28, 2019 , and excludes amounts already recorded on the consolidated balance sheet: Fiscal years ended (In thousands) Total 2020 2021 2022 2023 2024 Beyond Operating leases $ 83,483 $ 15,627 $ 14,759 $ 14,136 $ 14,395 $ 13,615 $ 10,951 Inventory 58,918 58,918 — — — — — Other noncancelable agreements 16,321 7,985 4,207 1,525 1,510 1,094 — Total contractual obligations $ 158,722 $ 82,530 $ 18,966 $ 15,661 $ 15,905 $ 14,709 $ 10,951 Legal proceedings From time to time, the Company is involved in legal proceedings in the ordinary course of business, including claims relating to employee relations, business practices and patent infringement. Litigation can be expensive and disruptive to normal business operations. Moreover, the results of complex legal proceedings are difficult to predict, and the Company’s view of these matters may change in the future as the litigation and events related thereto unfold. The Company expenses legal fees as incurred. The Company records a provision for contingent losses when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. An unfavorable outcome to any legal matter, if material, could have an adverse effect on the Company’s operations or its financial position, liquidity or results of operations. On March 10, 2017, Implicit, LLC ("Implicit") filed a patent infringement action in the United States District Court, District of Delaware against the Company. Implicit is asserting that the Company infringed on two patents in this case. The Company denies the allegations. There is no assurance of a favorable outcome and the Company’s business could be adversely affected as a result of a finding that the Company patents-in-suit are invalid and/or unenforceable. A range of loss, if any, associated with this matter is not probable or reasonably estimable as of September 28, 2019 and September 29, 2018. The Company is involved in certain other litigation matters not listed above but does not consider the matters to be material either individually or in the aggregate at this time. The Company’s view of the matters not listed may change in the future as the litigation and events related thereto unfold. Guarantees and indemnifications In the normal course of business, the Company enters into agreements that contain a variety of representations and warranties and provide for general indemnification. The Company’s exposure under these agreements is unknown because it involves claims that may be made against the Company in the future, but have not yet been made. 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 the Company 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 the Delaware General Corporation Law. The Company also currently has directors’ and officers’ insurance. No amount has been accrued in the financial statements with respect to these indemnification guarantees.

Quarterly financial data (unaud

Quarterly financial data (unaudited)	12 Months Ended
	Sep. 28, 2019
Quarterly Financial Information Disclosure [Abstract]
Quarterly financial data (unaudited)	Quarterly financial data (unaudited) The following table shows a summary of the Company’s unaudited quarterly financial information for each of the four quarters of 2019 and 2018 (the sum of quarterly periods may not equal full-year amounts due to rounding): Three Months Ended September 28, 2019 June 29, March 30, December 29, (In thousands, except per share amounts) Revenue $ 294,160 $ 260,119 $ 210,173 $ 496,371 Gross profit 124,271 117,370 90,413 195,289 Net income (loss) (29,600 ) (14,009 ) (22,824 ) 61,667 Net income (loss) per share - basic $ (0.28 ) $ (0.13 ) $ (0.22 ) $ 0.62 Net income (loss) per share - diluted $ (0.28 ) $ (0.13 ) $ (0.22 ) $ 0.55 Three Months Ended September 29, June 30, March 31, December 30, (In thousands, except per share amounts) Revenue $ 272,940 $ 208,398 $ 186,720 $ 468,950 Gross profit 116,277 95,489 81,341 196,201 Net income (loss) (1,720 ) (26,988 ) (32,592 ) 45,697 Net income (loss) per share - basic $ (0.02 ) $ (0.45 ) $ (0.55 ) $ 0.42 Net income (loss) per share - diluted $ (0.02 ) $ (0.45 ) $ (0.55 ) $ 0.36

Subsequent event

Subsequent event	12 Months Ended
	Sep. 28, 2019
Subsequent Events [Abstract]
Subsequent event	Subsequent event On November 14, 2019, the Company completed the acquisition of Snips SAS, a France-based provider of an artificial intelligence voice platform for connected devices that provides private-by-design, voice technology. Snips SAS will operate as a wholly-owned subsidiary of Sonos, Inc. The acquisition will be accounted for as a business combination, and we will begin consolidating Snips SAS’s financial results in our condensed consolidated financial statements in the first quarter of fiscal 2020. We acquired 100% of the equity interests of Snips SAS for approximately $ 37.5 million in cash, subject to purchase price adjustments and holdbacks. Given the recent date of the acquisition, we have not finalized our determination of the fair value of the assets acquired and liabilities assumed.

Summary of significant accoun_2

Summary of significant accounting policies (Policies)	12 Months Ended
	Sep. 28, 2019
Accounting Policies [Abstract]
Basis of presentation and preparation	Basis of presentation and preparation The consolidated financial statements, which include the accounts of Sonos, Inc. and its wholly owned subsidiaries, have been prepared in conformity with accounting principles generally accepted in the United States ("U.S. GAAP"). All intercompany accounts and transactions have been eliminated in consolidation. Certain prior period amounts have been reclassified to conform to the current period presentation. The Company operates on a 52- or 53- week fiscal year ending on the Saturday nearest September 30 each year. The Company’s fiscal year is divided into four quarters of 13 weeks, each beginning on a Sunday and containing two 4-week periods followed by a 5-week period. An additional week is included in the fourth fiscal quarter approximately every five years to realign fiscal quarters with calendar quarters. This occurred last in the fourth quarter of the Company’s fiscal year ended October 3, 2015 and will next reoccur in the fiscal year ended October 3, 2020. References to fiscal 2019 are to the Company’s fiscal year ended September 28, 2019 , references to fiscal 2018 are to the Company’s fiscal year ended September 29, 2018 and references to fiscal 2017 are to the Company’s fiscal year ended September 30, 2017 .
Use of estimates and judgments	Use of estimates and judgments The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and judgments that affect the amounts reported and disclosed in the consolidated financial statements and accompanying notes. Actual results could differ materially from those estimates. For revenue recognition, examples of estimates and judgments include: determining the nature and timing of satisfaction of performance obligations, determining the standalone selling price ("SSP") of performance obligations, estimating variable consideration such as sales incentives, and product returns. Additionally, estimates and judgments are made by management for allowances for doubtful accounts, the market value of and demand for inventory, useful lives associated with property and equipment, valuation allowances with respect to deferred tax assets and uncertain tax positions, impairment of long-lived assets, goodwill impairment, warranty, contingencies and valuation and assumptions underlying stock-based compensation and other equity instruments. On an ongoing basis, the Company evaluates its estimates and judgments compared to historical experience and trends that form the basis for making estimates and judgments about the carrying value of assets and liabilities.
Comprehensive loss	Comprehensive loss Comprehensive loss consists of two components: net loss and other comprehensive income (loss) . Other comprehensive income (loss) refers to net gains and losses that are recorded as an element of stockholders’ equity (deficit), but are excluded from net loss . The Company’s other comprehensive income (loss) consists of net unrealized gains and losses on foreign currency translation adjustments from those subsidiaries not using the U.S. dollar as their functional currency.
Cash and cash equivalents	Cash and cash equivalents Cash equivalents consist of short-term, highly liquid financial instruments with insignificant interest rate risk that are readily convertible to cash and have maturities of three months or less from the date of purchase. As of September 28, 2019 and September 29, 2018 , cash equivalents consisted of money market funds, which are recorded at fair value.
Restricted cash	Restricted cash The Company held $0.2 million in restricted cash as of September 28, 2019 and September 29, 2018 , representing security deposits on real estate leases.
Accounts receivable	Accounts receivable Accounts receivable are recorded at the invoiced amount less allowances for doubtful accounts and sales incentives, do not require collateral and do not bear interest. The allowance for doubtful accounts is established through a provision for net bad debt expense which is recorded in general and administrative expense in the consolidated statements of operations and comprehensive loss. The Company determines the adequacy of the allowance for doubtful accounts by evaluating customer accounts receivable balances as well as the customer’s financial condition, credit history and current economic conditions. This estimate is periodically adjusted as a result of the aforementioned process, or when the Company becomes aware of a specific customer’s inability to meet its financial obligations.
Concentration of credit risk	Concentration of credit risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist principally of cash and cash equivalents and accounts receivable. The Company maintains cash and cash equivalents in several high-quality financial institutions. Cash and cash equivalents held at these banks, including those held in foreign branches of global banks, may exceed the amount of insurance provided on such deposits. These deposits may be redeemed upon demand and management believes that the financial institutions that hold the Company’s cash and cash equivalents are financially sound and, accordingly, minimal credit risk exists with respect to cash. The Company has not experienced any losses in such accounts.
Inventories	Inventories Inventories primarily consist of finished goods and to a lesser extent component parts, which are purchased from contract manufacturers and component suppliers. Inventories are stated at lower of cost and net realizable value on a first-in, first-out basis. The Company assesses the valuation of inventory balances including an assessment to determine potential excess and/or obsolete inventory. The Company may be required to write down the value of inventory if estimates of future demand and market conditions indicate estimated excess or obsolete inventory. For the periods presented, the Company has not experienced significant write-downs.
Property and equipment, net	Property and equipment, net Property and equipment are stated at historical cost less accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets as follows: Computer hardware and software 2-3 years Furniture and fixtures 3-5 years Tooling and production line test equipment 2-4 years Leasehold improvements 2-10 years Product displays 1-3 years Costs incurred to improve leased office space are capitalized. Leasehold improvements are amortized on a straight-line basis over the shorter of the term of the lease or the estimated useful life of the improvement. Expenditures for major renewals and improvements that extend the useful lives of property and equipment are capitalized. Maintenance, repair costs and gains or losses associated with disposals are charged to expense as incurred. Product displays are deployed at retail locations. Because the product displays facilitate marketing of the Company’s products within the retail stores, depreciation for product displays is recorded in sales and marketing expenses in the consolidated statements of operations and comprehensive loss.
Impairment of long-lived assets	Impairment of long-lived assets The Company evaluates the recoverability of its long-lived assets, primarily comprised of property and equipment, for impairment whenever events or changes in circumstances indicate that the carrying amounts may not be recoverable. The Company performs impairment testing at the level that represents the lowest level for which identifiable cash flows are largely independent of the cash flows of other assets and liabilities. Recoverability is measured by comparing the carrying amounts to the expected future undiscounted cash flows attributable to the assets. If it is determined that an asset may not be recoverable, an impairment loss equal to the excess of the asset’s carrying value over its fair value is recorded. Fair value is determined based upon estimated discounted future cash flows.
Product warranties	Product warranties The Company’s products are covered by warranty to be free from defects in material and workmanship for a period of one year , except in the European Union and select other countries where the Company provides a two -year warranty on all its products. At the time of sale, an estimate of future warranty costs is recorded as a component of cost of revenue and a warranty liability is recorded for estimated costs to satisfy the warranty obligation. The Company’s estimate of costs to fulfill its warranty obligations is based on historical experience and expectations of future costs to repair or replace.
Legal contingencies	Legal contingencies If a potential loss from any claim or legal proceeding is considered probable, and the amount can be reasonably estimated, the Company accrues a liability for an estimated loss. Legal fees are expensed as incurred and included in general and administrative expenses in the consolidated statements of operations and comprehensive loss.
Treasury stock	Treasury stock The Company accounts for treasury stock acquisitions using the cost method. The Company accounts for the retirement of treasury stock by deducting its par value from common stock and reflecting any excess of cost over par value as a deduction from additional paid-in capital on the consolidated balance sheets.
Fair value accounting	Fair value accounting Assets and liabilities recorded at fair value on the consolidated balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair value. Fair value is estimated by applying the following hierarchy, which prioritizes the inputs used to measure fair value into three levels and bases the categorization within the hierarchy upon the lowest level of input that is available and significant to the fair value measurement: Level Input Input Definition Level 1 Quoted prices for identical assets or liabilities in active markets at the measurement date. Level 2 Inputs, other than quoted prices included in Level 1, such as quoted prices for similar assets or liabilities, in active markets or other inputs that are observable or can be corroborated with market data at the measurement date. Level 3 Unobservable inputs that reflect management's best estimate of what market participants would use in pricing the asset or liability at the measurement date.
Foreign currency	Foreign currency Certain of the Company’s wholly owned subsidiaries have non-U.S. dollar functional currencies. The Company translates assets and liabilities of non-U.S. dollar functional currency subsidiaries into U.S. dollars using exchange rates in effect at the end of each period and stockholders’ equity at historical rates. Revenue and expenses for these subsidiaries are translated using rates that approximate those in effect during the period. Gains and losses from translation are recognized in foreign currency translation included in accumulated other comprehensive loss . The Company remeasures monetary assets or liabilities denominated in currencies other than the functional currency using exchange rates prevailing on the balance sheet date, and non-monetary assets and liabilities at historical rates. Foreign currency remeasurement and transaction gains and losses are included in other income (expense), net. Foreign currency remeasurement and transaction gains (losses) are recorded in other income (expense), net and were $(8.6) million , $(1.2) million and $3.2 million for fiscal 2019 , 2018 and 2017 , respectively.
Revenue recognition	Revenue recognition Revenue is recognized upon transfer of control of promised products or services to customers in an amount that reflects the consideration the Company expects to receive in exchange for those products or services. The Company generally enters into contracts that include a combination of products and services. Revenue is allocated to distinct performance obligations and is recognized net of allowances for returns, discounts, sales incentives and any taxes collected from customers, which are subsequently remitted to governmental authorities. Shipping and handling costs associated with outbound freight after control over a product has transferred to a customer are accounted for as a fulfillment cost and are included in cost of revenue. As of September 28, 2019 and September 29, 2018 , the Company did not have any material assets related to incremental costs to obtain or fulfill customer contracts. In the prior year, the Company adopted ASC 606 using the full retrospective transition method which resulted in an acceleration of revenue and related costs of revenue and most significantly, a reduction in deferred costs and revenue and deferred revenue at each balance sheet date. Nature of products and services Product revenue includes sales of wireless speakers, home theater speakers and components, which include software that enables the Company’s products to operate over a customer’s wireless network, as well as connect to various third-party services, including music and voice. The Company also generates a small portion of revenue from other revenue sources such as sales of module units and Sonos and third-party accessories, which include speaker stands and wall mounts. Module revenue is comprised of hardware and embedded software that is integrated into final products that are manufactured and sold by the Company's partners. Software primarily consists of firmware embedded in the products and the Sonos app, which is software that can be downloaded to consumer devices at no charge, with or without the purchase of one of the Company’s products. Products and related software are accounted for as a single performance obligation and all intended functionality is available to the customer upon purchase. The revenue allocated to the products and related software is the substantial portion of the total sale price. Product revenue is recognized at the point in time when control is transferred, which is either upon shipment or upon delivery to the customer, depending on delivery terms. Service revenue includes revenue allocated to (i) unspecified software upgrades and (ii) cloud-based services that enable products to access third-party music and voice assistant platforms, which are each distinct performance obligations and are provided to customers at no additional charge. Unspecified software upgrades are provided on a when-and-if-available basis and have historically included updates and enhancements such as bug fixes, feature enhancements and updates to the ability to connect to third-party music or voice assistant platforms. Service revenue is recognized ratably over the estimated service period. Significant judgments The Company’s contracts with customers generally contain promises to transfer products and services as described above. Determining whether products and services are considered distinct performance obligations that should be accounted for separately requires significant judgment. Judgment is required to determine the SSP for each distinct performance obligation. The Company estimates SSP for items that are not sold separately, which include the products and related software, unspecified software upgrades and cloud-based services, using information that may include competitive pricing information, where available, as well as analyses of the cost of providing the products or services plus a reasonable margin. In developing SSP estimates, the Company also considers the nature of the products and services and the expected level of future services. Determining the revenue recognition period for unspecified software upgrades and cloud-based services also requires judgment. The Company recognizes revenue attributable to these performance obligations ratably over the best estimate of the period that the customer is expected to receive the services. In developing the estimated period of providing future services, the Company considers past history, plans to continue to provide services, including plans to continue to support updates and enhancements to prior versions of the Company’s products, expected technological developments, obsolescence, competition and other factors. The estimated service period may change in the future in response to competition, technology developments and the Company’s business strategy. The Company offers sales incentives through various programs consisting primarily of discounts, cooperative advertising and market development fund programs. The Company records cooperative advertising and market development fund programs with customers as a reduction to revenue unless it receives a distinct benefit in exchange for credits claimed by the customer and can reasonably estimate the fair value of the benefit received, in which case the Company records it as an expense. The Company recognizes a liability or a reduction to accounts receivable, and reduces revenue based on the estimated amount of sales incentives that will be claimed by customers. Estimates for sales incentives are developed using the most likely amount and are included in the transaction price to the extent that a significant reversal of revenue would not result once the uncertainty is resolved. In developing its estimate, the Company also considers the susceptibility of the incentive to outside influences, the length of time until the uncertainty is resolved and the Company’s experience with similar contracts. Reductions in revenue related to discounts are allocated to products and services on a relative basis based on their respective SSP. Judgment is required to determine the timing and amount of recognition of marketing funds which the Company estimates based on past practice of providing similar funds. The Company accepts returns from direct customers and from certain resellers. To establish an estimate for returns, the Company uses the expected value method by considering a portfolio of contracts with similar characteristics to calculate the historical returns rate. When determining the expected value of returns, the Company considers future business initiatives and relevant anticipated future events. Supplier concentration The Company relies on third parties for the supply and manufacture of its products, 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 or satisfactorily deliver its products to customers on time, if at all. During fiscal 2019 , 2018 and 2017 , approximately 83% , 98% and 99% , respectively, of the Company’s finished goods purchased during each year were from one vendor. Deferred revenue and payment terms The Company invoices each order upon hardware shipment or delivery and recognizes revenue for each distinct performance obligation when transfer of control has occurred, which in the case of services, may extend over several reporting periods. Amounts invoiced in advance of revenue recognition are recorded as deferred revenue on the consolidated balance sheets. Deferred revenue primarily relates to revenue allocated to unspecified software upgrades and platform services. The Company classifies deferred revenue as noncurrent if amounts are expected to be recognized as revenue after more than one year from the balance sheet date. Payment terms Payment terms and conditions vary among the Company’s distribution channels although terms generally include a requirement of payment within 30 days of product shipment. Sales directly to customers from the Company’s website are paid at the time of product shipment. Prior to providing payment terms to customers, an evaluation of the customer’s credit risk is performed. Contractual allowances are an offset to accounts receivable.
Research and development	Research and development Research and development expenses consist primarily of personnel-related expenses, consulting and outside professional service costs, tooling and prototype materials and overhead costs. Substantially all of the Company’s research and development expenses are related to developing new products and services and improving existing products and services. To date, software development costs have been expensed as incurred because the period between achieving technological feasibility and the release of the software has been short and development costs qualifying for capitalization have been insignificant.
Advertising costs	Advertising costs Advertising costs are expensed as incurred and included in sales and marketing expenses.
Share-based compensation	Stock-based compensation The Company measures stock-based compensation cost at fair value on the date of grant. Compensation cost for stock options is recognized, on a straight-line basis, as an expense over the period of vesting as the employee performs the related services, net of estimated forfeitures. The Company estimates the fair value of stock option awards using the Black-Scholes option-pricing model. The fair value of restricted stock units ("RSUs") is based on the Company's closing stock price on the trading day immediately preceding the date of grant and for stock options with graded vesting are recognized, on a straight-line basis, as an expense over the period of vesting as the employee performs the related services, net of estimated forfeitures. The Company estimates forfeitures based on expected future terminations and will revise rates, as necessary, in subsequent periods if actual forfeitures differ from initial estimates. Retirement Plans The Company has a defined contribution 401(k) plan (the "401(k) Plan") for the Company’s U.S.-based employees, as well as various benefit plans, principally defined contribution plans, for its international employees. Eligible U.S. employees may contribute up to 100% of their annual compensation under the 401(k) plan, but are limited to the maximum annual dollar amount allowable under the Internal Revenue Code of 1986, as amended (the "Code"). In the second quarter of fiscal 2019, the Company began making matching contributions towards the 401(k) Plan, as well as towards the international defined contribution plans.
Income taxes	Income taxes The Company accounts for income taxes under the asset and liability method, which requires the recognition of deferred tax assets and liabilities for the expected future tax consequences of events that have been included in the financial statements. Under this method, deferred tax assets and liabilities are determined based on the differences between the financial statements and tax basis of assets and liabilities using enacted tax rates in effect for the year in which the differences are expected to reverse. The effect of a change in tax rates on deferred tax assets and liabilities is recognized in income in the period that includes the enactment date. The Company records a valuation allowance to the extent that its deferred tax assets are not more likely than not to be realized. In making such a determination, all available positive and negative evidence is considered, including future reversals of existing taxable temporary differences, projected future taxable income, tax-planning strategies and results of recent operations. If the Company determines that it would be able to realize its deferred tax assets in the future in excess of their net recorded amount, the Company would make an adjustment to the deferred tax asset valuation allowance, which would reduce the provision for income taxes. The Company records uncertain tax positions in accordance with a two-step process whereby (i) the Company determines whether it is more likely than not that the tax positions will be sustained on the basis of the technical merits of the position and (ii) for those tax positions that meet the more likely than not recognition threshold, the Company recognizes the largest amount of tax benefit that is more than 50% likely to be realized upon ultimate settlement with the related tax authority. The Company includes interest and penalties related to unrecognized tax benefits within the provision for income taxes in the consolidated statements of operations and comprehensive loss. The Company has not incurred any interest or penalties related to unrecognized tax benefits in any of the periods presented. The Company’s provision for (benefit from) income taxes, deferred tax assets and liabilities and liabilities for unrecognized tax benefits involves the use of estimates, assumptions and judgments. Although the Company believes its estimates, assumptions and judgments to be reasonable, any changes in tax law or its interpretation of tax laws and the resolutions of potential tax audits could significantly impact the amounts provided for income taxes in the Company’s consolidated financial statements. Actual future operating results and the underlying amount and type of income could differ materially from the Company’s estimates, assumptions and judgments thereby impacting the Company’s financial position and results of operations.
Segment information	Segment information The Company operates as one operating segment as it only reports aggregate financial information on a consolidated basis, accompanied by disaggregated information about revenue by geographic region and product category to its Chief Executive Officer, who is the Company’s chief operating decision maker.
Leases	Leases The substantial majority of the Company’s leases are for its office spaces and facilities, which are accounted for as operating leases. For leases that contain rent escalation or rent concession provisions, the Company recognizes rent on a straight-line basis over the term of the lease. The Company does not assume renewals in its determination of the lease term unless the renewals are deemed to be reasonably assured at inception. Tenant improvement allowances received from landlords are recorded as a credit to deferred rent, reported as a liability on the consolidated balance sheets and amortized on a straight-line basis over the lease term as a reduction to rent expense in the consolidated statements of operations and comprehensive loss.
Recently adopted accounting pronouncements and recent accounting pronouncements pending adoption	Recently adopted accounting pronouncements Stock-based compensation In June 2018, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2018-07, Compensation—Stock Compensation (Topic 718): Improvements to Nonemployee Share-Based Payment Accounting , which aligns the accounting for share-based payment awards issued to nonemployees with the guidance applicable to grants to employees. Under this new standard, equity-classified share-based payment awards issued to nonemployees will be measured on the grant date, instead of the current requirement to remeasure the awards through the performance completion date. Further, compensation cost for awards with performance conditions will be recognized when it is probable the conditions will be achieved, rather than upon actual achievement of the conditions. In the second quarter of fiscal 2019, the Company early adopted the standard using the prospective approach. There was no cumulative effect entry needed to adjust the opening retained earnings balance upon adoption. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. Statement of cash flows In November 2016, the FASB issued ASU No. 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash , which enhances and clarifies the classification and presentation of restricted cash in the statement of cash flows. In the first quarter of fiscal 2019, the Company adopted this standard retrospectively to all periods presented. The Company now includes restricted cash and restricted cash equivalents with cash and cash equivalents when reconciling beginning and ending amounts shown on the statement of cash flows. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. In August 2016, the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, which reduces diversity in practice in how certain transactions are classified in the statement of cash flows. In the first quarter of fiscal 2019, the Company retrospectively adopted this standard to all periods presented. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. Income taxes In October 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other than Inventory . This guidance removes the prohibition in Accounting Standards Codification ("ASC") Topic 740, Income Taxes, against the immediate recognition of the current and deferred income tax effects of intra-entity transfers of assets other than inventory. ASU 2016-16 is intended to reduce the complexity of U.S. GAAP and diversity in practice related to the tax consequences of certain types of intra-entity asset transfers, particularly those involving intellectual property. In the first quarter of fiscal 2019, the Company adopted this standard on a modified retrospective basis. The adoption of this guidance did not have a material impact on the Company's consolidated financial statements. Recent accounting pronouncements pending adoption In February 2016, the FASB issued ASU No. 2016-02, Leases (Topic 842) , and other subsequent amendments, collectively referred to as Topic 842, which modifies lease accounting in order to increase transparency and comparability among entities. The standard requires lessees to recognize on the balance sheet, right-of-use assets and lease liabilities for the rights and obligations created by leases. In July 2018, the FASB issued ASU No. 2018-11, Leases (Topic 842): Targeted improvements, which provides an alternative transition method that entities can elect when adopting this standard. The Company plans to adopt the new standard effective September 29, 2019, using the optional transition method, recognizing a cumulative-effect adjustment to its balance of accumulated deficit at September 29, 2019 without restating comparative periods presented. The Company’s leases primarily include real estate leases and automobile leases. In adopting the new guidance, the Company will elect, amongst other practical expediencies, not to reassess (1) whether any expired or existing contracts contain leases under the new definition of a lease; (2) the lease classification for any expired or existing leases; and (3) whether previously capitalized initial direct costs would qualify for capitalization under Topic 842. Also, for leases with lease terms less than twelve months, an entity is permitted to make an accounting policy election by class of underlying asset not to recognize lease assets and lease liabilities. If a lessee makes this election, it should recognize lease expense for such leases generally on a straight-line basis over the lease term. The Company intends to make this election for all classes of assets. Upon adoption of this standard on September 29, 2019, the Company expects an increase in both total assets and total liabilities of approximately $60.0 million to $65.0 million. The Company does not believe that the adoption of the standard will have a material impact on the Company’s consolidated statements of operations and comprehensive loss or to the consolidated statements of cash flows. The Company continues to finalize the implementation of new processes and the assessment of the impact of this adoption on its consolidated financial statements; therefore, the preliminary estimated impacts disclosed can change and the final impact will be known once the adoption is completed during the first quarter of 2020. In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments , and other subsequent amendments including ASU 2019-04 Codification Improvements to Topic 326, Financial Instruments - Credit Losses, Topic 815, Derivatives and Hedging, and Topic 825, Financial Instruments , collectively referred to as Topic 326, which provides a new impairment model that require measurement and recognition of expected credit losses for most financial assets and certain other instruments, including but not limited to accounts receivable and available for sale debt securities. The standard will be effective for the Company in the first quarter of fiscal 2021. The Company is currently evaluating the impact on the Company's consolidated financial statements. In January 2017, the FASB issued ASU No. 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill , which simplifies the subsequent measurement of goodwill by eliminating the second step of the goodwill impairment test. The second step measures a goodwill impairment loss by comparing the implied fair value of a reporting unit's goodwill with the carrying amount of that goodwill. Under the new guidance, a company will record an impairment charge based on the excess of a reporting unit's carrying amount over its fair value. The standard will be effective for the Company in the first quarter of fiscal 2021, with early adoption permitted. The Company is currently evaluating the timing of adoption of the new standard . The Company expects the impact of ASU 2017-04 to be immaterial as goodwill was $1.0 million as of September 28, 2019 . In August 2018, the FASB issued ASU No. 2018-13, Fair Value Measurement (Topic 820): Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement .The new standard eliminates disclosures such as the amount of and reasons for transfers between Level 1 and Level 2 of the fair value hierarchy and adds new disclosure requirements for Level 3 measurements. The standard will be effective for the Company in the first quarter of fiscal 2021, with early adoption permitted. The Company is currently evaluating the timing of adoption and impact on the Company's consolidated financial statements. In August 2018, the FASB issued ASU No. 2018-15, Intangibles - Goodwill and Other - Internal-Use Software (Suptopic 350-40): Customer's Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract .The new guidance aligns the requirements for capitalizing implementation costs incurred in a cloud computing arrangement that is a service contract, with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The standard will be effective for the Company in the first quarter of fiscal 2021, with early adoption permitted. The Company is currently evaluating the timing of adoption and impact on the Company's consolidated financial statements. In November 2018, the FASB issued ASU No. 2018-18, Collaborative Arrangements (Topic 808): Clarifying the Interaction between Topic 808 and Topic 606 .This standard resolves the diversity in practice concerning whether certain transactions between collaborative arrangement participants should be accounted for as revenue under Accounting Standards Codification 606, Revenue from Contracts with Customers("Topic 606"). This standard specifies when a participant is a customer in a collaboration, adds unit of account guidance to align with Topic 606 and provides presentation guidance for collaborative arrangements. This standard will be effective for the Company in the first quarter of fiscal 2021, with early adoption permitted. The Company is currently evaluating the timing of adoption and impact on the Company's consolidated financial statements.

Summary of significant accoun_3

Summary of significant accounting policies (Tables)	12 Months Ended
	Sep. 28, 2019
Accounting Policies [Abstract]
Schedules of concentration of credit risk	As of September 28, 2019 and September 29, 2018 , the Company’s customers that accounted for 10% or more of total accounts receivable, net, were as follows: Accounts receivable, net 2019 2018 Customer A 20 % 31 % Customer B 14 % 13 % Customer C * 11 % Customer E 10 % * * Accounts receivable was less than 10%. The Company’s customers that accounted for 10% or more of total revenue were as follows: Revenue Year Ended 2019 2018 2017 Customer A 16 % 17 % 16 % Customer C 10 % 10 % 12 %
Schedule of property and equipment, depreciation	Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets as follows: Computer hardware and software 2-3 years Furniture and fixtures 3-5 years Tooling and production line test equipment 2-4 years Leasehold improvements 2-10 years Product displays 1-3 years Property and equipment, net by country as of September 28, 2019 and September 29, 2018 were as follows: 2019 2018 (In thousands) United States $ 48,370 $ 48,441 China 16,539 18,729 Other countries 13,230 18,201 Property and equipment, net $ 78,139 $ 85,371 Property and equipment, net consist of the following: 2019 2018 (In thousands) Computer hardware and software $ 47,775 $ 46,385 Furniture and fixtures 9,594 9,696 Tooling and production line test equipment 54,536 47,297 Leasehold improvements 58,944 53,962 Product displays 45,672 40,265 Total property and equipment 216,521 197,605 Accumulated depreciation and amortization (138,382 ) (112,234 ) Property and equipment, net $ 78,139 $ 85,371

Fair value measurements (Tables

Fair value measurements (Tables)	12 Months Ended
	Sep. 28, 2019
Fair Value Disclosures [Abstract]
Summary of fair value measurements by level for the assets measured on a recurring basis	The following table summarizes fair value measurements by level for the assets measured at fair value on a recurring basis as of September 28, 2019 and September 29, 2018 : 2019 (In thousands) Level 1 Level 2 Level 3 Total Assets: Money market funds (cash equivalents) $ 267,806 $ — $ — $ 267,806 2018 (In thousands) Level 1 Level 2 Level 3 Total Assets: Money market funds (cash equivalents) $ 140,588 $ — $ — $ 140,588

Revenue and geographic inform_2

Revenue and geographic information (Tables)	12 Months Ended
	Sep. 28, 2019
Revenue from Contract with Customer [Abstract]
Disaggregation of revenue	Disaggregation of revenue Revenue by geographical region, based on ship-to address, is as follows: 2019 2018 2017 (In thousands) Americas $ 678,224 $ 603,450 $ 496,668 Europe, Middle East and Africa ("EMEA") 484,785 478,518 442,081 Asia Pacific ("APAC") 97,814 55,040 53,777 Total revenue $ 1,260,823 $ 1,137,008 $ 992,526 Revenue from external customers is attributed to individual countries based on ship-to address. Revenue by significant countries is as follows: 2019 2018 2017 (In thousands) United States $ 630,012 $ 554,896 $ 449,261 Germany 124,385 121,546 111,065 United Kingdom 112,708 114,790 110,695 Other countries 393,718 345,776 321,505 Total revenue $ 1,260,823 $ 1,137,008 $ 992,526 Revenue by major product category is as follows: 2019 2018 2017 (In thousands) Wireless speakers $ 518,821 $ 546,649 $ 480,977 Home theater speakers 489,602 418,416 348,899 Components 188,861 150,436 151,965 Other 63,539 21,507 10,685 Total revenue $ 1,260,823 $ 1,137,008 $ 992,526
Schedule of property and equipment, net by country	Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets as follows: Computer hardware and software 2-3 years Furniture and fixtures 3-5 years Tooling and production line test equipment 2-4 years Leasehold improvements 2-10 years Product displays 1-3 years Property and equipment, net by country as of September 28, 2019 and September 29, 2018 were as follows: 2019 2018 (In thousands) United States $ 48,370 $ 48,441 China 16,539 18,729 Other countries 13,230 18,201 Property and equipment, net $ 78,139 $ 85,371 Property and equipment, net consist of the following: 2019 2018 (In thousands) Computer hardware and software $ 47,775 $ 46,385 Furniture and fixtures 9,594 9,696 Tooling and production line test equipment 54,536 47,297 Leasehold improvements 58,944 53,962 Product displays 45,672 40,265 Total property and equipment 216,521 197,605 Accumulated depreciation and amortization (138,382 ) (112,234 ) Property and equipment, net $ 78,139 $ 85,371

Balance sheet components (Table

Balance sheet components (Tables)	12 Months Ended
	Sep. 28, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of changes in allowance for doubtful accounts	The following table summarizes changes in the allowance for doubtful accounts for fiscal 2019 , 2018 and 2017 : 2019 2018 2017 (In thousands) Beginning balance $ 872 $ 804 $ 726 Increases 1,034 635 449 Write-offs (651 ) (567 ) (371 ) Ending balance $ 1,255 $ 872 $ 804
Summary of changes in allowance for sales incentives	The following table summarizes the changes in the allowance for sales incentives for fiscal 2019 , 2018 and 2017 : 2019 2018 2017 (In thousands) Beginning balance $ 11,754 $ 11,195 $ 8,913 Charged to revenue 87,703 90,246 65,879 Utilization of sales incentive allowance (79,406 ) (89,687 ) (63,597 ) Ending balance $ 20,051 $ 11,754 $ 11,195
Schedule of inventories, net	Inventories, net, consist of the following: 2019 2018 (In thousands) Finished goods $ 207,723 $ 176,181 Components 12,061 17,012 Inventories $ 219,784 $ 193,193
Schedule of property and equipment	Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets as follows: Computer hardware and software 2-3 years Furniture and fixtures 3-5 years Tooling and production line test equipment 2-4 years Leasehold improvements 2-10 years Product displays 1-3 years Property and equipment, net by country as of September 28, 2019 and September 29, 2018 were as follows: 2019 2018 (In thousands) United States $ 48,370 $ 48,441 China 16,539 18,729 Other countries 13,230 18,201 Property and equipment, net $ 78,139 $ 85,371 Property and equipment, net consist of the following: 2019 2018 (In thousands) Computer hardware and software $ 47,775 $ 46,385 Furniture and fixtures 9,594 9,696 Tooling and production line test equipment 54,536 47,297 Leasehold improvements 58,944 53,962 Product displays 45,672 40,265 Total property and equipment 216,521 197,605 Accumulated depreciation and amortization (138,382 ) (112,234 ) Property and equipment, net $ 78,139 $ 85,371
Schedule of accrued expenses	Accrued expenses consisted of the following: 2019 2018 (In thousands) Accrued advertising and marketing $ 25,662 $ 11,613 Accrued taxes 4,388 4,175 Accrued inventory 6,494 4,179 Accrued manufacturing, logistics and product development 14,783 8,290 Accrued general and administrative 12,455 3,322 Other accrued payables 6,074 7,108 Total accrued expenses $ 69,856 $ 38,687
Summary of changes in deferred revenue	The following table summarizes the changes in the deferred revenue balances: 2019 2018 2017 (In thousands) Deferred revenue, beginning of period $ 50,967 $ 45,567 $ 36,160 Recognition of revenue included in beginning of period deferred revenue (11,934 ) (10,627 ) (6,878 ) Revenue deferred, net of revenue recognized on contracts in the respective period 17,416 16,027 16,285 Deferred revenue, end of period $ 56,449 $ 50,967 $ 45,567
Schedule of expected recognition of deferred revenue	The Company expected the following recognition of deferred revenue as of September 28, 2019 : For the fiscal years ending (In thousands) 2020 2021 2022 2023 2024 and Beyond Total Revenue expected to be recognized $ 13,654 $ 12,143 $ 10,297 $ 8,369 $ 11,986 $ 56,449
Schedule of other current liabilities	Other current liabilities consist of the following: September 28, September 29, (In thousands) Reserve for returns $ 12,110 $ 5,005 Product warranty liability 3,254 2,450 Other 2,184 3,403 Total other current liabilities $ 17,548 $ 10,858
Schedule of warranty liability	The following table presents the changes in the Company’s warranty liability for the fiscal years ended September 28, 2019 and September 29, 2018 : September 28, September 29, (In thousands) Warranty liability, beginning of period $ 2,450 $ 2,437 Provision for warranties issued during the period 12,795 10,678 Settlements of warranty claims during the period (11,991 ) (10,665 ) Warranty liability, end of period $ 3,254 $ 2,450

Debt (Tables)

Debt (Tables)	12 Months Ended
	Sep. 28, 2019
Debt Disclosure [Abstract]
Schedule of short and long term debt	The Company’s short and long term debt as of September 28, 2019 and September 29, 2018 is as follows: 2019 2018 Rate Balance Rate Balance (In thousands) Term Loan (1) 4.6 % $ 33,333 4.8 % $ 40,000 Unamortized debt issuance costs (2) (160 ) (236 ) Total indebtedness 33,173 39,764 Less short term portion (8,333 ) (6,667 ) Long term debt $ 24,840 $ 33,097 (1) Bears interest at a variable rate equal to an adjusted LIBOR plus 2.25% and is payable quarterly. Due in October 2021, with quarterly principal payments beginning in July 2019. (2) Debt issuance costs are recorded as a debt discount and charged to interest expense over the term of the agreement.

Stock-based compensation (Table

Stock-based compensation (Tables)	12 Months Ended
	Sep. 28, 2019
Share-based Payment Arrangement [Abstract]
Schedule of stock option activity	The summary of the Company’s stock option activity is as follows: Number of Options Weighted Average Exercise Price Weighted Average Remaining Contractual Term Aggregate Intrinsic Value (in years) (in thousands) Outstanding at September 29, 2018 48,504,182 $ 10.33 6.6 $ 276,959 Granted 1,714,328 13.34 Exercised (7,925,897 ) 3.98 Forfeited (5,137,045 ) 13.48 Outstanding at September 28, 2019 37,155,568 $ 11.39 6.3 $ 94,288 At September 28, 2019 Options exercisable 26,436,074 $ 10.23 5.5 $ 92,281 Options vested and expected to vest 35,606,324 $ 11.25 6.2 $ 93,836
Schedule of fair value of options	The fair value of options at the date of grant was estimated with the following weighted-average assumptions: 2019 2018 2017 Expected term (years) 6.51 6.25 6.25 Risk-free interest rate 2.67 % 2.73 % 1.95 % Expected volatility 30.7 % 30.2 % 32.4 % Expected dividend yield — % — % — %
Schedule of restricted stock unit activity	The summary of the Company’s unvested RSU activity is as follows: Number of Units Weighted Average Grant Date Fair Value Aggregate Intrinsic Value (in thousands) Outstanding at September 29, 2018 — $ — $ — Granted 7,915,980 Exercised (829,270 ) Forfeited (369,924 ) Expired — Outstanding at September 28, 2019 6,716,786 $ 11.4 $ 90,744 At September 28, 2019 Units expected to vest 5,207,691 $ 11.4 $ 70,356
Schedule of stock-based compensation expense	Total stock-based compensation expense by function category was as follows: 2019 2018 2017 (In thousands) Cost of revenue $ 985 $ 198 $ 240 Research and development 17,643 13,960 13,605 Sales and marketing 12,965 15,885 15,086 General and administrative 14,982 8,602 7,619 Total stock-based compensation expense $ 46,575 $ 38,645 $ 36,550

Income taxes (Tables)

Income taxes (Tables)	12 Months Ended
	Sep. 28, 2019
Income Tax Disclosure [Abstract]
Schedule of income (loss) before provision for (benefit from) income taxes	The Company’s loss before provision for (benefit from) income taxes for fiscal 2019 , 2018 and 2017 were as follows: 2019 2018 2017 (In thousands) Domestic $ (858 ) $ 2,803 $ (25,005 ) Foreign (218 ) (17,351 ) 8,497 Loss before provision for (benefit from) income taxes $ (1,076 ) $ (14,548 ) $ (16,508 )
Schedule of provision for (benefit from) income taxes	Components of the provision for (benefit from) income taxes consisted of the following: 2019 2018 2017 (In thousands) Current: U.S. Federal $ 1,366 $ — $ — U.S. State 1,132 177 62 Foreign 1,463 816 (3,791 ) Total current 3,961 993 (3,729 ) Deferred: U.S. Federal — (168 ) — U.S. State — — — Foreign (271 ) 231 1,438 Total deferred (271 ) 63 1,438 Provision for (benefit from) income taxes $ 3,690 $ 1,056 $ (2,291 )
Schedule of deferred tax assets and liabilities	Components of the Company’s net deferred income tax assets (liabilities) are as follows: 2019 2018 (In thousands) Deferred tax assets Accrued expenses and reserves $ 12,582 $ 5,639 Deferred revenue 11,185 10,317 U.S. net operating loss carryforwards 15,112 18,385 Foreign net operating loss carryforwards 3,414 5,625 Tax credit carryforwards 43,411 22,969 Stock-based compensation 10,368 7,237 Amortization 4,131 3,237 Depreciation 672 — Other 453 427 Total deferred tax assets 101,328 73,836 Valuation allowance (95,088 ) (72,380 ) Deferred tax assets, net of valuation allowance 6,240 1,456 Deferred tax liabilities Tax accounting method change (5,086 ) — Depreciation — (515 ) Total deferred tax liabilities (5,086 ) (515 ) Net deferred tax assets $ 1,154 $ 941
Summary of changes in valuation allowance	The following table summarizes changes in the valuation allowance for fiscal 2019 , 2018 and 2017 : (In thousands) 2019 2018 2017 Beginning balance $ 72,380 $ 94,956 $ 95,882 Increase (decrease) during the period 22,708 (22,576 ) (926 ) Ending balance $ 95,088 $ 72,380 $ 94,956
Schedule of effective income tax rate reconciliation	Reconciliation of U.S. statutory federal income taxes to the Company’s provision for (benefit from) income taxes is as follows: (In thousands) 2019 2018 2017 U.S. federal income taxes at statutory rate $ (226 ) $ (3,570 ) $ (5,778 ) U.S. state and local income taxes (9,315 ) (1,441 ) (2,454 ) Foreign income tax rate differential 129 (53 ) (1,101 ) Dutch tax settlement — — 7,361 Stock-based compensation (2,399 ) 4,025 1,503 Federal research tax credits (8,418 ) (4,333 ) (2,978 ) Unrecognized federal tax benefits (2,806 ) 1,990 1,191 Change in tax rate 1,161 25,725 — Net Impact of GILTI 239 — — BEAT 781 — — Other 822 259 1,197 Change in valuation allowance 23,722 (21,546 ) (1,232 ) Provision for (benefit from) income taxes $ 3,690 $ 1,056 $ (2,291 )
Schedule of changes in unrecognized tax benefits	Change in unrecognized tax benefits as a result of uncertain tax positions are as follows: 2019 2018 (In thousands) Beginning balance $ 17,794 $ 13,780 Increase (decrease) - tax positions in prior periods (8,226 ) 636 Increase (decrease) - tax positions in current periods 2,959 3,378 Ending balance $ 12,527 $ 17,794

Net loss per share attributab_2

Net loss per share attributable to common stockholders (Tables)	12 Months Ended
	Sep. 28, 2019
Earnings Per Share [Abstract]
Schedule of net loss per share, basic	The following table sets forth the computation of the Company’s basic and diluted net loss per share attributable to common stockholders: 2019 2018 2017 (In thousands, except share and per share data) Numerator: Net loss attributable to common stockholders - basic and diluted $ (4,766 ) $ (15,604 ) $ (14,217 ) Denominator: Weighted-average shares of common stock - basic and diluted 103,783,006 65,706,215 56,314,546 Net loss per share attributable to common stockholders: Net loss per share attributable to common stockholders - basic and diluted $ (0.05 ) $ (0.24 ) $ (0.25 )
Schedule of potentially dilutive shares excluded from computation of diluted earnings per share	The following potentially dilutive shares as of the end of each period presented were excluded from the computation of diluted net loss per share for the periods presented because including them would have been antidilutive: 2019 2018 2017 Stock options to purchase common stock 42,300,183 48,504,182 45,817,252 RSUs 4,147,463 — — Convertible preferred stock — — 32,482,590 Shares subject to repurchase — — 53,892 Total 46,447,646 48,504,182 78,353,734

Commitments and contingencies (

Commitments and contingencies (Tables)	12 Months Ended
	Sep. 28, 2019
Commitments and Contingencies Disclosure [Abstract]
Schedule of noncancelable payments	The following table presents noncancelable payments due by the Company as of September 28, 2019 , and excludes amounts already recorded on the consolidated balance sheet: Fiscal years ended (In thousands) Total 2020 2021 2022 2023 2024 Beyond Operating leases $ 83,483 $ 15,627 $ 14,759 $ 14,136 $ 14,395 $ 13,615 $ 10,951 Inventory 58,918 58,918 — — — — — Other noncancelable agreements 16,321 7,985 4,207 1,525 1,510 1,094 — Total contractual obligations $ 158,722 $ 82,530 $ 18,966 $ 15,661 $ 15,905 $ 14,709 $ 10,951

Quarterly financial data (una_2

Quarterly financial data (unaudited) (Tables)	12 Months Ended
	Sep. 28, 2019
Quarterly Financial Information Disclosure [Abstract]
Schedule of unaudited quarterly financial information	The following table shows a summary of the Company’s unaudited quarterly financial information for each of the four quarters of 2019 and 2018 (the sum of quarterly periods may not equal full-year amounts due to rounding): Three Months Ended September 28, 2019 June 29, March 30, December 29, (In thousands, except per share amounts) Revenue $ 294,160 $ 260,119 $ 210,173 $ 496,371 Gross profit 124,271 117,370 90,413 195,289 Net income (loss) (29,600 ) (14,009 ) (22,824 ) 61,667 Net income (loss) per share - basic $ (0.28 ) $ (0.13 ) $ (0.22 ) $ 0.62 Net income (loss) per share - diluted $ (0.28 ) $ (0.13 ) $ (0.22 ) $ 0.55 Three Months Ended September 29, June 30, March 31, December 30, (In thousands, except per share amounts) Revenue $ 272,940 $ 208,398 $ 186,720 $ 468,950 Gross profit 116,277 95,489 81,341 196,201 Net income (loss) (1,720 ) (26,988 ) (32,592 ) 45,697 Net income (loss) per share - basic $ (0.02 ) $ (0.45 ) $ (0.55 ) $ 0.42 Net income (loss) per share - diluted $ (0.02 ) $ (0.45 ) $ (0.55 ) $ 0.36

Business overview (Details)

Business overview (Details) $ / shares in Units, $ in Thousands	Aug. 06, 2018USD ($)$ / sharesshares	Sep. 28, 2019USD ($)country	Sep. 29, 2018USD ($)	Sep. 30, 2017USD ($)
Class of Stock [Line Items]
Number of countries where products distributed | country		50
Underwriting discounts and commissions		$ 585	$ 3,950	$ 0
Preferred stock automatically converted into common stock (in shares) | shares	32,482,590
Convertible preferred stock, conversion ratio	1
IPO
Class of Stock [Line Items]
Shares sold in IPO (in shares) | shares	15,972,221
Public offering price (in dollars per share) | $ / shares	$ 15
Net proceeds from IPO	$ 90,600
Underwriting discounts and commissions	5,300
Offering costs	$ 4,600

Summary of significant accoun_4

Summary of significant accounting policies - Textual (Details)	Jul. 19, 2018	Sep. 28, 2019USD ($)operating_segment	Sep. 29, 2018USD ($)	Sep. 30, 2017USD ($)	Sep. 29, 2019USD ($)
Product Warranty Liability [Line Items]
Stock split, conversion ratio	2
Restricted cash		$ 179,000	$ 190,000
Impairment of long-lived assets		$ 0	0	$ 0
Product warranty term		1 year
Foreign currency remeasurement and transaction gain (losses)		$ (4,035,000)	(941,000)	3,568,000
401(k) plan maximum annual contribution per employee		100.00%
Number of operating segments (in segment) | operating_segment		1
Operating lease liability		$ 60,000,000
Operating lease asset		60,000,000
Goodwill		$ 1,000,000
Accounting Standards Update 2016-02 | Subsequent Event
Product Warranty Liability [Line Items]
Operating lease liability					$ 65,000,000
Operating lease asset					$ 65,000,000
European Union
Product Warranty Liability [Line Items]
Product warranty term		2 years
Other income (expense)
Product Warranty Liability [Line Items]
Foreign currency remeasurement and transaction gain (losses)		$ (8,600,000)	(1,200,000)	3,200,000
Sales and marketing
Product Warranty Liability [Line Items]
Advertising costs		$ 48,800,000	$ 50,200,000	$ 72,200,000
One vendor | Supplier concentration risk
Product Warranty Liability [Line Items]
Concentration percentage		83.00%	98.00%	99.00%

Summary of significant accoun_5

Summary of significant accounting policies - Percentage accounts receivable, revenue (Details)	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Customer A | Accounts receivable
Product Information [Line Items]
Concentration percentage	20.00%	31.00%
Customer A | Revenue
Product Information [Line Items]
Concentration percentage	16.00%	17.00%	16.00%
Customer B | Accounts receivable
Product Information [Line Items]
Concentration percentage	14.00%	13.00%
Customer C | Accounts receivable
Product Information [Line Items]
Concentration percentage		11.00%
Customer C | Revenue
Product Information [Line Items]
Concentration percentage	10.00%	10.00%	12.00%
Customer E | Accounts receivable
Product Information [Line Items]
Concentration percentage	10.00%

Summary of significant accoun_6

Summary of significant accounting policies - Property and equipment, net (Details)	12 Months Ended
	Sep. 28, 2019
Computer hardware and software | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Computer hardware and software | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Furniture and fixtures | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years
Furniture and fixtures | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	5 years
Tooling and production line test equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Tooling and production line test equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	4 years
Leasehold improvements | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	2 years
Leasehold improvements | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	10 years
Product displays | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	1 year
Product displays | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	3 years

Fair value measurements (Detail

Fair value measurements (Details) - Money market funds - Fair value, measurements, recurring - USD ($) $ in Thousands	Sep. 28, 2019	Sep. 29, 2018
Assets:
Money market funds (cash equivalents)	$ 267,806	$ 140,588
Level 1
Assets:
Money market funds (cash equivalents)	267,806	140,588
Level 2
Assets:
Money market funds (cash equivalents)	0	0
Level 3
Assets:
Money market funds (cash equivalents)	$ 0	$ 0

Revenue and geographic inform_3

Revenue and geographic information - Disaggregation of revenues (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Revenue	$ 294,160	$ 260,119	$ 210,173	$ 496,371	$ 272,940	$ 208,398	$ 186,720	$ 468,950	$ 1,260,823	$ 1,137,008	$ 992,526
Wireless speakers
Disaggregation of Revenue [Line Items]
Revenue									518,821	546,649	480,977
Home theater speakers
Disaggregation of Revenue [Line Items]
Revenue									489,602	418,416	348,899
Components
Disaggregation of Revenue [Line Items]
Revenue									188,861	150,436	151,965
Other
Disaggregation of Revenue [Line Items]
Revenue									63,539	21,507	10,685
Americas
Disaggregation of Revenue [Line Items]
Revenue									678,224	603,450	496,668
Europe, Middle East and Africa (EMEA)
Disaggregation of Revenue [Line Items]
Revenue									484,785	478,518	442,081
Asia Pacific (APAC)
Disaggregation of Revenue [Line Items]
Revenue									97,814	55,040	53,777
United States
Disaggregation of Revenue [Line Items]
Revenue									630,012	554,896	449,261
Germany
Disaggregation of Revenue [Line Items]
Revenue									124,385	121,546	111,065
United Kingdom
Disaggregation of Revenue [Line Items]
Revenue									112,708	114,790	110,695
Other countries
Disaggregation of Revenue [Line Items]
Revenue									$ 393,718	$ 345,776	$ 321,505

Revenue and geographic inform_4

Revenue and geographic information - Disaggregation of property and equipment, net (Details) - USD ($) $ in Thousands	Sep. 28, 2019	Sep. 29, 2018
Property, Plant and Equipment [Line Items]
Property and equipment, net	$ 78,139	$ 85,371
United States
Property, Plant and Equipment [Line Items]
Property and equipment, net	48,370	48,441
China
Property, Plant and Equipment [Line Items]
Property and equipment, net	16,539	18,729
Other countries
Property, Plant and Equipment [Line Items]
Property and equipment, net	$ 13,230	$ 18,201

Balance sheet components - Summ

Balance sheet components - Summary of changes in allowance for doubtful accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 872	$ 804	$ 726
Increases	1,034	635	449
Write-offs	(651)	(567)	(371)
Ending balance	$ 1,255	$ 872	$ 804

Balance sheet components - Su_2

Balance sheet components - Summary of changed in allowance for sales incentives (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Allowance for Sales Incentives [Roll Forward]
Beginning balance	$ 11,754	$ 11,195	$ 8,913
Charged to revenue	87,703	90,246	65,879
Utilization of sales incentive allowance	(79,406)	(89,687)	(63,597)
Ending balance	$ 20,051	$ 11,754	$ 11,195

Balance sheet components - Inve

Balance sheet components - Inventories (Details) - USD ($) $ in Thousands	Sep. 28, 2019	Sep. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Finished goods	$ 207,723	$ 176,181
Components	12,061	17,012
Inventories	$ 219,784	$ 193,193

Balance sheet components - Prop

Balance sheet components - Property and equipment, net (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 216,521	$ 197,605
Accumulated depreciation and amortization	(138,382)	(112,234)
Property and equipment, net	78,139	85,371
Depreciation	36,415	39,358	$ 35,014
Fixed asset, disposal	10,200	35,800	11,500
Fixed asset disposal, accumulated depreciation	9,300	35,600	11,200
Loss on disposal of fixed assets	800	200	$ 200
Computer hardware and software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	47,775	46,385
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	9,594	9,696
Tooling and production line test equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	54,536	47,297
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	58,944	53,962
Product displays
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 45,672	$ 40,265

Balance sheet components - Accr

Balance sheet components - Accrued expenses (Details) - USD ($) $ in Thousands	Sep. 28, 2019	Sep. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued advertising and marketing	$ 25,662	$ 11,613
Accrued taxes	4,388	4,175
Accrued inventory	6,494	4,179
Accrued manufacturing, logistics and product development	14,783	8,290
Accrued general and administrative	12,455	3,322
Other accrued payables	6,074	7,108
Total accrued expenses	$ 69,856	$ 38,687

Balance sheet components - Chan

Balance sheet components - Change in deferred revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Contract with Customer, Liability [Roll Forward]
Deferred revenue, beginning of period	$ 50,967	$ 45,567	$ 36,160
Recognition of revenue included in beginning of period deferred revenue	(11,934)	(10,627)	(6,878)
Revenue deferred, net of revenue recognized on contracts in the respective period	17,416	16,027	16,285
Deferred revenue, end of period	$ 56,449	$ 50,967	$ 45,567

Balance sheet components - Expe

Balance sheet components - Expected recognition of deferred revenue (Details) $ in Thousands	Sep. 28, 2019USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue expected to be recognized	$ 56,449
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-09-29
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue expected to be recognized	$ 13,654
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-04
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue expected to be recognized	$ 12,143
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-10-03
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue expected to be recognized	$ 10,297
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	3 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-02
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue expected to be recognized	$ 8,369
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	4 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-10-01
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Revenue expected to be recognized	$ 11,986
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period

Balance sheet components - Othe

Balance sheet components - Other current liabilities (Details) - USD ($) $ in Thousands	Sep. 28, 2019	Sep. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Reserve for returns	$ 12,110	$ 5,005
Product warranty liability	3,254	2,450
Other	2,184	3,403
Total other current liabilities	$ 17,548	$ 10,858

Balance sheet components - Ch_2

Balance sheet components - Changes in warranty liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Warranty liability, beginning of period	$ 2,450	$ 2,437
Provision for warranties issued during the year	12,795	10,678
Settlements of warranty claims during the year	(11,991)	(10,665)
Warranty liability, end of period	$ 3,254	$ 2,450

Debt - Schedule of debt (Detail

Debt - Schedule of debt (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Debt Instrument [Line Items]
Rate	4.60%	4.81%
Balance	$ 33,333	$ 40,000
Unamortized debt issuance costs	(160)	(236)
Total indebtedness	33,173	39,764
Less short term portion	(8,333)	(6,667)
Long-term debt	$ 24,840	$ 33,097
London interbank offered rate (LIBOR) | New Term Loan
Debt Instrument [Line Items]
Interest rate, spread on variable rate	2.25%

Debt - Textual (Details)

Debt - Textual (Details)	12 Months Ended
	Sep. 28, 2019USD ($)	Sep. 29, 2018USD ($)	Oct. 31, 2015USD ($)
Debt Instrument [Line Items]
Outstanding borrowings	$ 4,500,000	$ 4,500,000
Line of credit | New term loan
Debt Instrument [Line Items]
Fixed charge ratio, Covenant 2	1	1
Fixed charge ratio, Covenant 1	1.15	1.15
Revolving credit facility | Line of credit
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 80,000,000
Fixed charge ratio, Covenant 2	1	1
Fixed charge ratio, Covenant 1	1.15	1.15
London interbank offered rate (LIBOR) | New term loan
Debt Instrument [Line Items]
Interest rate, spread on variable rate	2.25%
London interbank offered rate (LIBOR) | Revolving credit facility | Line of credit
Debt Instrument [Line Items]
Interest rate, spread on variable rate	2.50%

Stockholders' equity - Textual

Stockholders' equity - Textual information (Details)	Aug. 06, 2018$ / sharesshares	Sep. 28, 2019$ / sharesshares	Sep. 03, 2019USD ($)	Sep. 29, 2018$ / sharesshares
Equity [Abstract]
Preferred stock automatically converted into common stock (in shares)	32,482,590
Convertible preferred stock, conversion ratio	1
Common stock, authorized (in shares)	500,000,000	500,000,000		151,458,824
Common stock, par value (in dollars per share) | $ / shares	$ 0.001	$ 0.001		$ 0.001
Preferred stock, authorized (in shares)	10,000,000
Preferred stock, par value (in dollars per share) | $ / shares	$ 0.001
Stock repurchase program, authorized value | $			$ 50,000,000

Stock-based compensation - Addi

Stock-based compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended	12 Months Ended
	Jul. 31, 2018	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options granted, fair value		$ 8.4	$ 50.2	$ 39.4
Weighted-average grant date fair value (in dollars per share)		$ 4.91	$ 5.39	$ 4.84
Fair value of options vested		$ 34.3	$ 38.3	$ 34.8
Intrinsic value of stock options exercised		61.1	31.3	$ 42
Unrecognized stock-based compensation expense		$ 43.9	$ 71.5
Stock options to purchase common stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		48 months
Unrecognized stock-based compensation expense, period of recognition		2 years	2 years 7 months 6 days
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		4 years
Unrecognized stock-based compensation expense, period of recognition		3 years 5 months
Unrecognized stock-based compensation expense		$ 55.6
2003 Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance (in shares)	21,839,258
Outstanding shares increase for future issuance	5.00%
2018 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares reserved for future issuance (in shares)		25,280,393
Exercisable period		10 years

Stock-based compensation - Stoc

Stock-based compensation - Stock option activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Number of Options
Beginning balance (in shares)	48,504,182
Granted (in shares)	1,714,328
Exercised (in shares)	(7,925,897)
Forfeited (in shares)	(5,137,045)
Ending balance (in shares)	37,155,568	48,504,182
Options exercisable (in shares)	26,436,074
Options vested and expected to vest (in shares)	35,606,324
Weighted Average Exercise Price
Beginning balance (in dollars per share)	$ 10.33
Granted (in dollars per share)	13.34
Exercised (in dollars per share)	3.98
Forfeited (in dollars per share)	13.48
Ending balance (in dollars per share)	11.39	$ 10.33
Option exercisable (in dollars per share)	10.23
Options vested and expected to vest (in dollars per share)	$ 11.25
Additional Information
Weighted Average Remaining Contractual Term	6 years 4 months	6 years 7 months
Option exercisable - Weighted Average Remaining Contractual Term	5 years 6 months
Options vested and expected to vest - Weighted Average Remaining Contractual Term	6 years 2 months
Aggregate Intrinsic Value	$ 94,288	$ 276,959
Options exercisable - Weighted Average Intrinsic Value	92,281
Options vested and expected to vest - Weighted Average Intrinsic Value	$ 93,836

Stock-based compensation - Fair

Stock-based compensation - Fair value of options (Details)	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Share-based Payment Arrangement [Abstract]
Expected term (years)	6 years 6 months 5 days	6 years 3 months	6 years 3 months
Risk-free interest rate	2.67%	2.73%	1.95%
Expected volatility	30.70%	30.20%	32.40%
Expected dividend yield	0.00%	0.00%	0.00%

Share-based compensation - Rest

Share-based compensation - Restricted Stock Units Activity (Details) - RSUs - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding, beginning balance (in shares)	0
Granted (in shares)	7,915,980
Exercised (in shares)	(829,270)
Forfeited (in shares)	(369,924)
Expired (in shares)	0
Outstanding, ending balance (in shares)	6,716,786
Units expected to vest (in shares)	5,207,691
Outstanding (in usd per share)	$ 11.4	$ 0
Aggregate Intrinsic Value	$ 90,744	$ 0
Vested and expected to vest - Weighted Average Exercise Price (in dollars per share)	$ 11.4
Vested and expected to vest - Weighted Average Intrinsic Value	$ 70,356

Stock-based compensation - St_2

Stock-based compensation - Stock-based compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 46,575	$ 38,645	$ 36,550
Cost of revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	985	198	240
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	17,643	13,960	13,605
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	12,965	15,885	15,086
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Stock-based compensation expense	$ 14,982	$ 8,602	$ 7,619

Income taxes - Income (loss) be

Income taxes - Income (loss) before income tax provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
Domestic	$ (858)	$ 2,803	$ (25,005)
Foreign	(218)	(17,351)	8,497
Loss before provision for (benefit from) income taxes	$ (1,076)	$ (14,548)	$ (16,508)

Income taxes - Components of pr

Income taxes - Components of provision (benefit) for income taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Current:
U.S. Federal	$ 1,366	$ 0	$ 0
U.S. State	1,132	177	62
Foreign	1,463	816	(3,791)
Total current	3,961	993	(3,729)
Deferred:
U.S. Federal	0	(168)	0
U.S. State	0	0	0
Foreign	(271)	231	1,438
Total deferred	(271)	63	1,438
Provision for (benefit from) income taxes	$ 3,690	$ 1,056	$ (2,291)

Income taxes - Deferred tax ass

Income taxes - Deferred tax assets and liabilities (Details) - USD ($) $ in Thousands	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016
Deferred tax assets
Accrued expenses and reserves	$ 12,582	$ 5,639
Deferred revenue	11,185	10,317
U.S. net operating loss carryforwards	15,112	18,385
Foreign net operating loss carryforwards	3,414	5,625
Tax credit carryforwards	43,411	22,969
Stock-based compensation	10,368	7,237
Amortization	4,131	3,237
Depreciation	672	0
Other	453	427
Total deferred tax assets	101,328	73,836
Valuation allowance	(95,088)	(72,380)	$ (94,956)	$ (95,882)
Deferred tax assets, net of valuation allowance	6,240	1,456
Deferred tax liabilities
Tax accounting method change	(5,086)	0
Depreciation	0	(515)
Total deferred tax liabilities	(5,086)	(515)
Net deferred tax assets	$ 1,154	$ 941

Income taxes - Textual (Details

Income taxes - Textual (Details) $ in Millions	Sep. 28, 2019USD ($)
Operating Loss Carryforwards [Line Items]
Undistributed earnings	$ 5.9
Withholding tax liability	0.5
Federal
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	60.6
Federal | Research tax credit carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	33.8
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	36.2
State | Research tax credit carryforward
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	25.9
Foreign
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	16.1
Foreign | Tax year expiration, indefinite
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	1.4
Foreign | Tax year expiration, 2027
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 14.7

Income taxes - Valuation allowa

Income taxes - Valuation allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Valuation Allowance [Roll Forward]
Beginning balance	$ 72,380	$ 94,956	$ 95,882
Increase (decrease) during the period	22,708	(22,576)	(926)
Ending balance	$ 95,088	$ 72,380	$ 94,956

Income taxes - Effective tax re

Income taxes - Effective tax reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Income Tax Disclosure [Abstract]
U.S. federal income taxes at statutory rate	$ (226)	$ (3,570)	$ (5,778)
U.S. state and local income taxes	(9,315)	(1,441)	(2,454)
Foreign income tax rate differential	129	(53)	(1,101)
Dutch tax settlement	0	0	7,361
Stock-based compensation	(2,399)	4,025	1,503
Federal research tax credits	(8,418)	(4,333)	(2,978)
Unrecognized federal tax benefits	(2,806)	1,990	1,191
Change in tax rate	1,161	25,725	0
Net Impact of GILTI	239	0	0
BEAT	781	0	0
Other	822	259	1,197
Change in valuation allowance	23,722	(21,546)	(1,232)
Provision for (benefit from) income taxes	$ 3,690	$ 1,056	$ (2,291)

Income taxes - Changes in unrec

Income taxes - Changes in unrecognized tax benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 17,794	$ 13,780
Increase (decrease) - tax positions in prior periods	(8,226)
Increase (decrease) - tax positions in prior periods		636
Increase (decrease) - tax positions in current periods	2,959	3,378
Ending balance	$ 12,527	$ 17,794

Net loss per share attributab_3

Net loss per share attributable to common stockholders - Narrative (Details)	Aug. 06, 2018shares
Earnings Per Share [Abstract]
Preferred stock automatically converted into common stock (in shares)	32,482,590
Convertible preferred stock, conversion ratio	1

Net loss per share attributab_4

Net loss per share attributable to common stockholders - Computation of basic and diluted earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Numerator:
Net loss attributable to common stockholders - basic and diluted	$ (4,766)	$ (15,604)	$ (14,217)
Denominator:
Weighted-average shares of common stock—basic and diluted (in shares)	103,783,006	65,706,215	56,314,546
Net loss per share attributable to common stockholders:
Net loss per share attributable to common stockholders - basic and diluted (in dollars per share)	$ (0.05)	$ (0.24)	$ (0.25)

Net loss per share attributab_5

Net loss per share attributable to common stockholders - Antidilutive securities excluded from computation of earnings per share (Details) - shares	12 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	46,447,646	48,504,182	78,353,734
Stock options to purchase common stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	42,300,183	48,504,182	45,817,252
RSUs
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	4,147,463	0	0
Convertible preferred stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	0	0	32,482,590
Shares subject to repurchase
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation (in shares)	0	0	53,892

Commitments and contingencies -

Commitments and contingencies - Textual (Details) $ in Millions	Mar. 10, 2017patent	Sep. 28, 2019USD ($)	Sep. 29, 2018USD ($)	Sep. 30, 2017USD ($)
Loss Contingencies [Line Items]
Operating leases, rent expense | $		$ 13.7	$ 14.5	$ 13.5
Minimum
Loss Contingencies [Line Items]
Operating lease, term of contract		1 year
Maximum
Loss Contingencies [Line Items]
Operating lease, term of contract		10 years
Implicit, LLC
Loss Contingencies [Line Items]
Loss Contingency, Patents Allegedly Infringed, Number | patent	2

Commitments and contingencies_2

Commitments and contingencies - Contractual obligations (Details) $ in Thousands	Sep. 28, 2019USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Total	$ 83,483
2020	15,627
2021	14,759
2022	14,136
2023	14,395
2024	13,615
Beyond	10,951
Total contractual obligations
Total	158,722
2020	82,530
2021	18,966
2022	15,661
2023	15,905
2024	14,709
Beyond	10,951
Other noncancelable agreements
Total	16,321
2020	7,985
2021	4,207
2022	1,525
2023	1,510
2024	1,094
Beyond	0
Inventory
Total contractual obligations
Total	58,918
2020	58,918
2021	0
2022	0
2023	0
2024	0
Beyond	$ 0

Quarterly financial data (una_3

Quarterly financial data (unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Sep. 28, 2019	Jun. 29, 2019	Mar. 30, 2019	Dec. 29, 2018	Sep. 29, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 30, 2017	Sep. 28, 2019	Sep. 29, 2018	Sep. 30, 2017
Quarterly Financial Information Disclosure [Abstract]
Revenue	$ 294,160	$ 260,119	$ 210,173	$ 496,371	$ 272,940	$ 208,398	$ 186,720	$ 468,950	$ 1,260,823	$ 1,137,008	$ 992,526
Gross profit	124,271	117,370	90,413	195,289	116,277	95,489	81,341	196,201	527,343	489,308	456,065
Net income (loss)	$ (29,600)	$ (14,009)	$ (22,824)	$ 61,667	$ (1,720)	$ (26,988)	$ (32,592)	$ 45,697	$ (4,766)	$ (15,604)	$ (14,217)
Net income (loss) per share - basic (in dollars per share)	$ (0.28)	$ (0.13)	$ (0.22)	$ 0.62	$ (0.02)	$ (0.45)	$ (0.55)	$ 0.42
Net income (loss) per share - diluted (in dollars per share)	$ (0.28)	$ (0.13)	$ (0.22)	$ 0.55	$ (0.02)	$ (0.45)	$ (0.55)	$ 0.36

Subsequent event (Details)

Subsequent event (Details) - Snips SAS - Subsequent Event $ in Millions	Nov. 14, 2019USD ($)
Subsequent Event [Line Items]
Percentage of business acquired	100.00%
Purchase price of business combination	$ 37.5