ViewRay (VRAYQ) 10-K 28 Mar 16 2015 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Mar. 25, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Entity Registrant Name	ViewRay, Inc.
Entity Central Index Key	1,597,313
Document Type	10-K
Trading Symbol	VRAY
Document Period End Date	Dec. 31, 2015
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Smaller Reporting Company
Entity Common Stock, Shares Outstanding		38,216,523
Entity Public Float			$ 0
Entity Current Reporting Status	No
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Document Fiscal Period Focus	FY
Document Fiscal Year Focus	2,015

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 20,667,000	$ 11,129,000
Accounts receivable	830,000	904,000
Inventory	8,073,000	8,238,000
Deposits on purchased inventory	3,936,000	2,798,000
Deferred cost of revenue	8,782,000	4,712,000
Prepaid expenses and other current assets	1,329,000	626,000
Total current assets	43,617,000	28,407,000
Property and equipment, net	7,306,000	2,931,000
Restricted cash	943,000	1,053,000
Intangible assets, net	200,000	264,000
Deferred offering costs	0	1,419,000
Other assets	91,000	31,000
TOTAL ASSETS	52,157,000	34,105,000
Current liabilities:
Accounts payable	4,358,000	6,937,000
Accrued liabilities	5,413,000	3,633,000
Customer deposits	12,763,000	6,100,000
Deferred revenue, current portion	5,616,000	7,361,000
Long-term debt, current portion	0	5,493,000
Notes payable	0	240,000
Total current liabilities	28,150,000	29,764,000
Long-term debt, net of current portion	29,016,000	9,149,000
Convertible preferred stock warrant liability	0	138,000
Deferred revenue, net of current portion	345,000	0
Other long-term liabilities	1,603,000	567,000
TOTAL LIABILITIES	$ 59,114,000	$ 39,618,000
Commitments and contingencies (Note 7)
Convertible preferred stock, par value $0.01 per share; 80,710,997 and 74,460,997 shares authorized at December 31, 2015 and 2014; nil and 27,654,928 shares issued and outstanding at December 31, 2015 and 2014; aggregate liquidation preference of nil and $146,732 at December 31, 2015 and 2014	$ 0	$ 145,110,000
Stockholders’ deficit:
Common stock, par value of $0.01 per share; 90,000,000 and 88,000,000 shares authorized at December 31, 2015 and 2014; 38,204,960 and 907,037 shares issued and outstanding at December 31, 2015 and 2014	372,000	9,000
Additional paid-in capital	189,712,000	1,414,000
Accumulated deficit	(197,041,000)	(152,046,000)
TOTAL STOCKHOLDERS’ DEFICIT	(6,957,000)	(150,623,000)
TOTAL LIABILITIES, CONVERTIBLE PREFERRED STOCK AND STOCKHOLDERS’ DEFICIT	$ 52,157,000	$ 34,105,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Convertible preferred stock, shares authorized	80,710,997	74,460,997
Convertible preferred stock, shares outstanding		27,654,928
Convertible preferred stock, aggregate liquidation preference		$ 146,732
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	90,000,000	88,000,000
Common stock, shares issued	38,204,960	907,037
Common stock, shares outstanding	38,204,960	907,037
Convertible Preferred Stock
Convertible preferred stock, par value	$ 0.01	$ 0.01
Convertible preferred stock, shares authorized	80,710,997	74,460,997
Convertible preferred stock, shares issued	0	27,654,928
Convertible preferred stock, shares outstanding	0	27,654,928
Convertible preferred stock, aggregate liquidation preference	$ 0	$ 146,732

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue:
Product	$ 9,620	$ 5,988	$ 2,253
Service	530	411	12
Grant	240	0	894
Total revenue	10,390	6,399	3,159
Cost of revenue:
Product	12,673	8,176	8,173
Service	1,871	975	14
Total cost of revenue	14,544	9,151	8,187
Gross margin	(4,154)	(2,752)	(5,028)
Operating expenses:
Research and development	10,449	9,404	8,780
Selling and marketing	5,139	4,681	3,781
General and administrative	21,685	14,742	9,508
Total operating expenses	37,273	28,827	22,069
Loss from operations	(41,427)	(31,579)	(27,097)
Interest income	2	1	4
Interest expense	(3,452)	(2,243)	(97)
Other income (expense), net	(117)	21	(32)
Loss before provision for income taxes	(44,994)	(33,800)	(27,222)
Provision for income taxes	1	0	0
Net loss	(44,995)	(33,800)	(27,222)
Cumulative dividends on convertible preferred stock	0	0	(2,898)
Deemed capital conversion of Series C convertible preferred stock into common stock	0	0	8,783
Deemed dividend on convertible preferred stock extinguishment	0	0	(6,863)
Deemed capital contribution on repurchase of Series A preferred stock	0	9	0
Net loss attributable to common stockholders	$ (44,995)	$ (33,791)	$ (28,200)
Net loss per share attributable to common stockholders, basic and diluted	$ (2.58)	$ (37.87)	$ (34.59)
Weighted-average common shares used to compute net loss per share attributable to common stockholders, basic and diluted	17,432,434	892,315	815,340

Consolidated Statements of Conv

Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit - USD ($) $ in Thousands	Total	Series C Convertible Preferred Stock	Series C Convertible Preferred Stock2014 Convertible Promissory Notes	Series B Convertible Preferred Stock [Member]	Private Placement	Convertible Preferred Stock	Convertible Preferred StockSeries D-1 Convertible Preferred Stock	Convertible Preferred StockSeries D-2 Convertible Preferred Stock	Convertible Preferred StockSeries C Convertible Preferred Stock	Convertible Preferred StockSeries C Convertible Preferred Stock2014 Convertible Promissory Notes	Convertible Preferred StockSeries B Convertible Preferred Stock [Member]	Common Stock	Common StockSeries C Convertible Preferred Stock	Common StockPrivate Placement	Additional Paid-in Capital	Additional Paid-in CapitalSeries C Convertible Preferred Stock	Additional Paid-in CapitalPrivate Placement	Accumulated Deficit	Accumulated DeficitSeries C Convertible Preferred Stock	Accumulated DeficitSeries B Convertible Preferred Stock [Member]	Holders of MiraxCommon Stock
Temporary equity balance at Dec. 31, 2012						$ 79,540
Temporary equity balance , shares at Dec. 31, 2012						16,748,405
Balance at Dec. 31, 2012	$ (89,274)											$ 8			$ 773			$ (90,055)
Balance, shares at Dec. 31, 2012												730,203
Issuance of common stock from option exercises	$ 1														1
Issuance of common stock from option exercises, shares	1,463											1,463
Issuance of convertible preferred stock							$ 4,901	$ 15,030	$ 14,929
Issuance of convertible preferred stock, shares							983,558	3,013,797	2,564,638
Accrued dividends	$ (2,898)																	(2,898)
Conversion of convertible securities, value		$ 8,887		$ (6,863)				$ 16,249	$ (7,475)		$ 112,080		$ 1			$ 103			$ 8,783	$ (6,863)
Conversion of convertible securities, shares						22,308,230		3,196,417	(1,470,485)		22,308,230		147,051
Extinguishment of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock						$ (105,217)
Extinguishment of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock, shares						(22,308,230)
Stock-based compensation	219														219
Issuance stock						2,564,638
Net loss	(27,222)																	(27,222)
Temporary equity balance at Dec. 31, 2013						$ 130,037
Temporary equity balance , shares at Dec. 31, 2013						25,036,330
Balance at Dec. 31, 2013	(117,150)											$ 9			1,096			(118,255)
Balance, shares at Dec. 31, 2013												878,717
Issuance of common stock from option exercises	$ 21														21
Issuance of common stock from option exercises, shares	28,320											28,320
Repurchase of Series A convertible preferred stock and deemed capital contribution	$ 9					$ (25)												9
Repurchase of Series A convertible preferred stock and deemed capital contribution, shares						(1,353)
Issuance of convertible preferred stock									$ 4,969
Issuance of convertible preferred stock, shares									880,546
Conversion of convertible securities, value										$ 10,129
Conversion of convertible securities, shares			1,739,405			1,739,405				1,739,405
Stock-based compensation	297														297
Issuance stock						880,546
Net loss	(33,800)																	(33,800)
Temporary equity balance at Dec. 31, 2014	$ 145,110	$ 30,027		$ 112,080		$ 145,110
Temporary equity balance , shares at Dec. 31, 2014	27,654,928	5,184,589		22,308,230		27,654,928
Balance at Dec. 31, 2014	$ (150,623)											$ 9			1,414			(152,046)
Balance, shares at Dec. 31, 2014												907,037
Issuance of common stock from option exercises	$ 24														24
Issuance of common stock from option exercises, shares	31,427											31,427
Issuance of convertible preferred stock									$ 15,729
Issuance of convertible preferred stock, shares									2,727,059
Conversion of convertible securities, value	$ 160,839					$ (160,839)						$ 304			160,535
Conversion of convertible securities, shares			1,739,405			(30,381,987)						30,381,987
Stock-based compensation	1,066														1,066
Issuance of common stock value private placement					$ 26,323									$ 59			$ 26,264
Issuance stock						2,727,059								5,884,504							1,000,005
Conversion of convertible preferred stock warrants into common stock warrants in connection with the Merger	93														93
Issuance of common stock warrants to placement agent as payment for services	316														316
Net loss	(44,995)																	(44,995)
Temporary equity balance at Dec. 31, 2015	0
Balance at Dec. 31, 2015	$ (6,957)											$ 372			$ 189,712			$ (197,041)
Balance, shares at Dec. 31, 2015												38,204,960

Consolidated Statements of Con6

Consolidated Statements of Convertible Preferred Stock and Stockholders' Deficit (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accrued interest	$ 0	$ 142
Private Placement
Offering cost	3,125	0	$ 0
Series C Convertible Preferred Stock
Issuance cost	221	181	71
Series D-1 Convertible Preferred Stock
Issuance cost	0	0	99
Series D-2 Convertible Preferred Stock
Issuance cost	0	0	291
2014 Convertible Promissory Notes | Series C Convertible Preferred Stock
Accrued interest	0	173	0
Unamortized debt discount	$ 0	$ 44	$ 0

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (44,995)	$ (33,800)	$ (27,222)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,256	1,020	1,149
Stock-based compensation	1,066	318	$ 219
Change in fair value of convertible preferred stock warrant liability	(45)	(20)
Inventory lower of cost and market adjustment	2,578	598	$ 4,582
Write-off of deferred offering cost	2,920
Amortization of debt discount and interest accrual	1,129	446	8
Loss on disposal of property and equipment	12	8	176
Accretion on asset retirement obligation	8
Changes in operating assets and liabilities:
Accounts receivable	74	(650)	(254)
Inventory	(2,413)	(3,279)	(5,175)
Deposits on purchased inventory	(1,138)	(479)	(879)
Deferred cost of revenue	(4,070)	(4,712)
Prepaid expenses and other current assets	(703)	13	(167)
Other assets	(30)	28	(37)
Accounts payable	(2,053)	4,033	(666)
Notes payable	(240)
Accrued expenses and other long-term liabilities	1,532	(1,048)	2,074
Customer deposits and deferred revenue	5,263	10,055	821
Net cash used in operating activities	(39,849)	(27,469)	(25,371)
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of property and equipment	(4,151)	(2,003)	(1,198)
Purchase of intangible and other assets	(104)		(500)
Change in restricted cash balance	110	(600)	105
Net cash used in investing activities	(4,145)	(2,603)	(1,593)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of convertible notes, net		9,941
Repurchase of Series A convertible preferred stock		(37)
Proceeds from issuance of convertible preferred stock, net	15,729	4,969	34,860
Proceeds from draw down of long-term debt	30,000		14,534
Payment of debt issuance cost	(1,132)
Payments of long-term debt	(15,000)
Proceeds from common stock private placement, gross	29,447
Payment of offering costs related to common stock private placement	(2,808)
Payments of costs related to the initial public offering	(2,728)	(222)
Proceeds from the exercise of stock options	24	21	1
Net cash provided by financing activities	53,532	14,672	49,395
NET INCREASE (DECREASE) IN CASH	9,538	(15,400)	22,431
CASH — Beginning of period	11,129	26,529	4,098
CASH — End of period	20,667	11,129	26,529
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	2,332	1,504
Cash paid for taxes	1
SUPPLEMENTAL NON-CASH INVESTING AND FINANCING ACTIVITIES:
Conversion of convertible preferred stock warrants into common stock warrants in connection with the Merger	160,839
Conversion of convertible notes into new Series C convertible preferred stock		10,129
Purchase of fixed assets in accounts payable and accrued expenses	1,136	62	59
Fair value of common stock warrants issued to placement agents as payment for service	316
Asset retirement obligation	258
Conversion of convertible preferred stock warrants into common stock warrants	93
Cumulative dividends on convertible preferred stock	$ 0	0	2,898
Issuance of convertible preferred stock warrant			158
Costs related to the initial public offering included in accounts payable and accrued liabilities		$ 1,197
Series C Convertible Preferred Stock
SUPPLEMENTAL NON-CASH INVESTING AND FINANCING ACTIVITIES:
Conversion convertible preferred stock			8,887
Series D-2 Convertible Preferred Stock
SUPPLEMENTAL NON-CASH INVESTING AND FINANCING ACTIVITIES:
Conversion convertible preferred stock			16,249
Series B Convertible Preferred Stock [Member]
SUPPLEMENTAL NON-CASH INVESTING AND FINANCING ACTIVITIES:
Conversion convertible preferred stock			$ 6,863

Background and Organization

Background and Organization	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Background and Organization	1. Background and Organization On July 23, 2015, ViewRay, Inc. (f/k/a Mirax Corp.), or the Company, and ViewRay Technologies, Inc. (f/k/a ViewRay Incorporated), consummated an Agreement and Plan of Merger and Reorganization, or Merger Agreement. Pursuant to the Merger Agreement, the stockholders of ViewRay Technologies, Inc. contributed all of their equity interests to the Company for shares of the Company’s common stock and merged with the Company’s subsidiary, which resulted in ViewRay Technologies, Inc. becoming a wholly-owned subsidiary of the Company (the Merger). Refer to Note 3 for further information on the Merger. ViewRay, Inc. and its wholly-owned subsidiary ViewRay Technologies, Inc., designs, manufactures and markets MRIdian, the first and only MRI-guided radiation therapy system to image and treat cancer patients simultaneously. Since inception, ViewRay Technologies, Inc. has devoted substantially all of its efforts towards research and development, initial selling and marketing activities, raising capital and preparing for the manufacturing and shipment of MRIdian systems. In May 2012, ViewRay Technologies, Inc. was granted clearance from the U.S. Food and Drug Administration, or FDA, to sell MRIdian. In November 2013, ViewRay Technologies, Inc. received its first clinical acceptance of a MRIdian at a customer site, and the first patient was treated with that system in January 2014. Since November 2014, ViewRay Technologies, Inc. has the right to affix the CE mark to MRIdian. The Company’s consolidated financial statements have been prepared on the basis of the Company continuing as a going concern for a reasonable period of time. The Company’s principal sources of liquidity are cash flows from investment capital and available borrowings under its Term Loan agreement. These have historically been sufficient to meet working capital needs, capital expenditures, and debt service obligations. During the year ended December 31, 2015, the Company incurred a net loss from operations of $45.0 million and used cash from operations of $39.8 million. The Company plans that it will have sufficient cash flows from its operations to continue as a going concern, however these plans rely on certain underlying assumptions and estimates that may differ from actual results. Such assumptions include FDA approval of the Company’s MRIdian linac technology, which may broaden the Company’s addressable market, accelerate the Company’s sales cycle, accelerate backlog conversion time and improve gross margins. The Company’s plans also included the ability to execute Amendment No. 1 to the Capital Royalty Partners, L.P. debt agreement (see Note 6) to provide access to an additional $15.0 million of working capital. This action was completed in the first quarter of 2016 and will provide liquidity in addition to the forecasted operating cash flows to meet working capital needs, capital expenditures and debt service obligations for the next twelve months.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies The accompanying consolidated financial statements reflect the application of certain significant accounting policies, as described below and elsewhere in the accompanying notes to the consolidated financial statements. Basis of Presentation The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP, and pursuant to the rules and regulation of the Securities and Exchanges Commission, or SEC. The consolidated financial statements include the accounts of ViewRay, Inc. and its wholly-owned subsidiary, ViewRay Technologies, Inc. All significant inter-company accounts and transactions have been eliminated in consolidation. Certain amounts in the consolidated balance sheet at December 31, 2014 were reclassified to conform to the current year presentation. These reclassifications did not affect the previously reported total assets, total liabilities, consolidated statements of operations or stockholders’ deficit. Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the consolidated financial statements and accompanying notes. Such estimates include, but are not limited to, allocation of revenue to its multiple deliverable elements, inventory write-downs to reflect net realizable value, assumptions used in the valuation of stock-based awards and a convertible preferred stock warrant, accrued losses from purchase commitments and valuation allowances against deferred tax assets. Actual results could differ from those estimates. Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. The Company deposits its cash primarily in checking and money market accounts. Restricted Cash At December 31, 2015, and 2014, the Company had an aggregate of $0.9 million and $1.1 million of outstanding letters of credit related to its operating leases and its contractual obligations with distributors and customers. The letters of credit are collateralized by a restricted cash deposit account, which is presented as part of noncurrent assets on the balance sheets because the Company is not certain when the restriction will be lifted on the collateralized letters of credit. At December 31, 2015, and 2014, no amounts were drawn on the letters of credit. Concentration of Credit Risk, Other Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. Cash and cash equivalents are deposited in checking and money market accounts with various financial institutions. At times, cash balances may be in excess of the amounts insured by the Federal Deposit Insurance Corporation. Management believes the financial risk associated with these balances is minimal and has not experienced any losses to date. The Company performs periodic credit evaluations of its customers’ financial condition and generally requires deposits from its customers. The Company’s accounts receivable was derived from billings to customers. The Company’s customers representing greater than 10% of accounts receivable and revenue for the periods presented were as follows: Revenue Accounts Receivables Year Ended December 31, December 31, Customers 2015 2014 2013 2015 2014 Customer A * * 72% * * Customer B * 52% * * * Customer C * 40% * * * Customer D 48% * * * 100% Customer E 43% * * 94% * State of Ohio * * 28% * * The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, rapid technological change, continued acceptance of MRIdian, competition from substitute products and larger companies, protection of proprietary technology, ability to maintain distributor relationships and dependence on key individuals. Furthermore, new products to be developed by the Company require approval from the FDA or other international regulatory agencies prior to commercial sales. There can be no assurance that the Company’s future products will receive the necessary clearances. The Company relies on a concentrated number of suppliers to manufacture essentially all of the components used in MRIdian. The Company’s suppliers may encounter problems during manufacturing due to a variety of reasons, including failure to comply with applicable regulations, including the FDA’s Quality System Regulation, equipment malfunction and environmental factors, any of which could delay or impede their ability to meet demand. Accounts Receivables and Allowance for Doubtful Accounts Accounts receivable are recorded at the invoiced amount, net of any allowance for doubtful accounts, and do not bear interest. The allowance for doubtful accounts, if any, is based on the assessment of the collectability of customer accounts. Based on the specific customer and the current economic conditions, there was no allowance for doubtful accounts recorded at December 31, 2015 and 2014. Fair Value of Financial Instruments Financial instruments consist of cash and cash equivalents, accounts receivable, restricted cash, prepaid expenses and other current assets, accounts payable, accrued liabilities, notes payable, convertible preferred stock warrant liability and long-term debt. Cash equivalents are stated at amortized cost, which approximates fair value at the balance sheet dates, due to the short period of time to maturity. Accounts receivable, prepaid expenses and other current assets, accounts payable, accrued liabilities and notes payable are stated at their carrying value, which approximates fair value due to the short time to the expected receipt or payment date. The convertible preferred stock warrant liability is carried at fair value. The carrying amount of the Company’s long-term debt approximates fair value as the stated interest rate approximates market rates currently available to the Company. Inventory and Deposits on Purchased Inventory Inventory consists of purchased components for assembling MRIdian systems and other direct and indirect costs associated with MRIdian system installation. Inventory is stated at the lower of cost or market value. All inventories expected to be placed in service during normal operating cycle of ViewRay Technologies, Inc. for the delivery and assembly of MRIdian systems, including items expected to be on hand for more than one year, are classified as current assets. Effective January 1, 2015, ViewRay Technologies, Inc. made a voluntary change to its accounting policy for inventory cost basis. Under the previous accounting policy, inventory items were recorded on a first-in, first-out basis through specific identification. Purchased components were assigned to each MRIdian system at original cost. Under the new accounting policy, ViewRay Technologies, Inc. recorded inventory at weighted average cost basis. The Company believes that this change is preferable because it will be more efficient for the Company to keep track of its inventory cost. The first-in, first-out cost basis through specific identification accounting policy was manageable at the time when ViewRay Technologies, Inc. had limited MRIdian system installations (one MRIdian system installation during the year ended December 31, 2013, and another two MRIdian system installation during the year ended December 31, 2014). However, due to the Company’s growing business and sales, the number of planned MRIdian system installation has been increasing. Purchased components are no longer assigned to specific MRIdian system installation. Along with the Company’s increased components purchasing activities, the new accounting policy will significantly reduce the Company’s burden and cost of inventory management. In accordance with applicable accounting literature, a change in inventory cost basis is treated as a change in accounting principle and requires retrospective application. The accounting policy change has no cumulative effect on ViewRay Technologies, Inc. annual statements of operations prior to January 1, 2015. Therefore, no retrospective adjustment for the Company’s annual consolidated financial statements are required. The Company reduces the carrying value of its inventory for the difference between cost and net realizable value and records a charge to cost of product revenues for the amount required to reduce the carrying value of inventory to net realizable value. The Company recorded an inventory lower of cost and market adjustment of $2.6 million, $598 thousand and $4.6 million during the years ended December 31, 2015, 2014 and 2013, respectively. The Company records inventory items which have been paid for but not yet received and titles have not yet transferred to the Company as deposits on purchased inventory. Deposits on purchased inventory are included within current assets as the related inventory items are expected to be received and used in MRIdian systems within the Company’s normal operating cycle. The Company assesses the recoverability of deposits on purchased inventory based on credit assessments of the vendors and their history supplying these assets. At December 31, 2015, the Company did not have any instances whereby deposits for purchased inventory were written off or the purchased inventory was not delivered. Shipping and Handling Costs Shipping and handling costs for product shipments to customers are included in cost of product revenue. Shipping and handling costs incurred for inventory purchases are capitalized in inventory and expensed in cost of product revenue. These costs are not passed on to customers. Property and Equipment Property and equipment are recorded at cost. Depreciation is computed over estimated useful lives, ranging from two to 15 years of the related assets using the straight-line method. Acquired software is recorded at cost. Amortization of acquired software generally occurs over three years using the straight-line method. Leasehold improvements are amortized on a straight-line basis over the shorter of the useful life or term of the lease. Upon retirement or sale, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is recorded to general and administrative expense in the accompanying statements of operations. Routine expenditures for maintenance and repairs are expensed as incurred. Depreciation and amortization periods for property and equipment are as follows: Property and Equipment Estimated Useful Life Prototype 2 years Machinery and equipment 5 – 15 years Furniture and fixture 5 – 10 years Software 3 years Leasehold improvements Lesser of estimated useful life or remaining lease term Asset Retirement Obligation In connection with certain lease agreements entered into in October 2015, the Company has a legal requirement to remove long-lived assets constructed on leased property and to restore the leased property to its original condition. The Company records the fair value of the liability for a legal obligation to retire an asset in the period in which the obligation is incurred if a reasonable estimate of fair value can be made. The Company measures the fair value of the asset retirement obligation based upon the present value of the expected future payments, and recognized asset retirement obligation of $250,000 at inception. The liability is accreted to its present value each period and the capitalized cost is depreciated over the remaining lease term. Accretion expense is calculated by applying the effective interest rate to the carrying amount of the liability at the beginning of each period. The effective interest rate is the credit-adjusted risk-free rate applied when the liability was initially measured and recognized. At December 31, 2015, the Company had outstanding asset retirement obligations of $258,000, which was included in other long-term liabilities in the accompanying consolidated balance sheets. For the year ended December 31, 2015, the Company recognized accretion expenses of $8,000 in the accompanying statement of operations. Intangible Assets Intangible assets consist primarily of patents and license acquisition costs associated with certain technology components incorporated into the Company’s MRIdian systems. The Company capitalizes the cost and amortizes it on a straight-line basis over the estimated useful lives, which is generally three years for license cost and five to seven years for patents. Impairment of Long-Lived Assets The Company reviews the recoverability of long-lived assets, including equipment, leasehold improvements, software and intangible assets when events or changes in circumstances occur that indicate that the carrying value of the asset may not be recoverable. The assessment of possible impairment is based on the ability to recover the carrying value of the assets from the expected future cash flows (undiscounted and without interest charge) of the related operations. If these cash flows are less than the carrying value of such assets, an impairment loss for the difference between the estimated fair value and carrying value is recorded. There was no impairment loss recognized during the years ended December 31, 2015, 2014 and 2013. Deferred Offering Costs ViewRay Technologies, Inc. capitalizes qualified legal, accounting and other direct costs related to its efforts to raise capital through a public sale of its common stock in its planned IPO. These costs are recorded in deferred offering costs in the accompanying balance sheets and will be Comprehensive Loss Comprehensive loss is the change in equity of a company during a period from transactions and other events and circumstances, excluding transactions resulting from investment owners and distribution to owners. For the periods presented, comprehensive loss did not differ from net loss. Revenue Recognition The Company derives revenue primarily from the sale of the systems and related services, which are predominantly sales of MRIdian, as well as support and maintenance services on purchased systems. In all sales arrangements, the Company recognizes revenues when there is persuasive evidence of an arrangement, the fee is fixed or determinable, collection of the fee is reasonably assured and delivery has occurred. For sales of MRIdian systems, the Company currently recognizes product revenue upon receipt of customer acceptance. For sales of the related support and maintenance services, the Company recognizes service revenue on a straight-line basis over the service contract term, which is typically 12 months. Multiple Elements Based on the nature of the Company’s business, it frequently enters into sales arrangements with customers that contain multiple elements or deliverables. In situations where a deliverable in a multi-element arrangement has value to the customer on a stand-alone basis, the Company is required to allocate the fair value of the various elements based on the selling price of each element. The principal deliverables consist of (i) sale of MRIdian systems, which generally includes installation, site preparation and software, and (ii) product support, which includes extended service and maintenance. The Company determines selling prices using vendor specific objective evidence, or VSOE, if it exists, or third party evidence, or TPE. If neither VSOE nor TPE exists for a deliverable, the Company uses best estimated selling price, or BESP. The Company allocates revenue to its multiple elements generally using the relative fair values as determined by BESP. The Company regularly reviews VSOE, TPE and BESP for all of its MRIdian systems and services. Product Revenue Product revenue is derived primarily from the sales of MRIdian. The system contains both software and non-software components that together deliver essential functionality. However, because MRIdian includes hardware products as well as software components that function together with the hardware components to deliver MRIdian’s essential functionality, the revenue from the sale of MRIdian systems does not fall within the scope of the software revenue recognition rules. The related customer contracts currently call for on-site assembly of the system components and system integration. Once the system installation is completed, the Company performs a detailed demonstration with the customer showing that MRIdian meets the standard product specifications. After successful demonstration, the customer signs a document indicating customer acceptance. All contracts include customer deposits upon signing of the agreement with final payment generally due upon customer acceptance. Revenue recognition for MRIdian systems generally occurs when the customer acknowledges that the system operates in accordance with standard product specifications, the customer accepts the installed unit and title and risk of loss are transferred to the customer. Service Revenue Service revenue is derived primarily from maintenance services. Service revenue is deferred and recognized ratably over the service period. Grant Revenue The Company receives payments for the achievement of certain milestones under government grants over a contractually defined period. These payments are nonrefundable. Government grants generally provide the Company with fixed payments and a contractually defined period. Grant revenues are recognized as milestones under the grant program are achieved and is earned through reimbursements for the qualifying expenses incurred by the Company. The Company retains ownership and exclusive rights to all inventions made under these arrangements. Upon the completion of the Company’s government grants, no further obligations exist under these arrangements. The Company retains the rights to commercialize the technology it developed under government grants without any royalty obligations. The Company entered into a loan agreement with the county redevelopment fund in the State of Ohio to fund the renovation of its Ohio headquarters. Under the terms of the loan agreement, the lender may forgive a portion of the loan if the Company meets certain permanent job creation requirement within the State of Ohio. Grant revenues are recognized when the Company meets the employment requirement and receives the loan forgiveness notice from the lender. Customer Deposits Customer deposits represent payments received in advance of system installation. For domestic sales, advance payments received prior to customer acceptance are recorded as customer deposits. For international sales, advance payments are initially recorded as customer deposits and are subsequently reclassified to deferred revenue upon inventory shipment when the title and risk of loss of inventory items transferred to customers. All customer deposits, including those that are expected to be a deposit for more than one year, are classified as current liabilities based on consideration of the Company’s normal operating cycle (the time between acquisition of the inventory components and the final cash collection from customers on these inventory components) which is in excess of one year. Deferred Revenue and Deferred Cost of Revenue Deferred revenue consists of deferred product revenue and deferred service revenue. Deferred product revenue arises from timing differences between the fulfillment of other contract deliverables and satisfaction of all revenue recognition criteria consistent with the Company’s revenue recognition policy. Deferred service revenue results from the advance billing for services to be delivered over a period of time. Deferred revenues expected to be realized within one year are classified as current liabilities. Deferred cost of revenue consists of cost for inventory items that have been shipped with title and risk of loss transferred to customer but the customer acceptance has not been received. Deferred cost of revenue is included as part of current assets as the corresponding deferred product revenue are expected to be realized within one year. The inventories recorded in deferred cost of revenue are also included in the inventory lower of cost or market analysis. At December 31, 2015 and 2014, no reserve was required for deferred cost of revenue. Research and Development Costs Expenditures, including payroll, contractor expenses and supplies, for research and development of products and manufacturing processes are expensed as incurred. Software development costs incurred subsequent to establishing technological feasibility are capitalized through the general release of MRIdian systems that contain the embedded software elements. Technological feasibility is demonstrated by the completion of a working model. The Company has not capitalized any software development costs at December 31, 2015 or 2014, since the costs incurred subsequent to achieving technological feasibility and completing the research and development for the software components were immaterial. Stock-Based Compensation The Company uses the Black-Scholes option-pricing model as the method for estimating the fair value of stock options. The Black-Scholes option-pricing model requires the use of highly subjective and complex assumptions that determine the fair value of share-based awards, including the options’ expected term and the price volatility of the underlying stock. The fair value of the portion of the award that is ultimately expected to vest is recognized as compensation expense over the awards’ requisite service periods in the statements of operations. The Company attributes the value of share-based compensation to expense using the straight-line method. Medical Device Excise Tax Medical Device Excise Tax, or MDET, Section 4191 of the Internal Revenue Code enacted by the Health Care and Education Reconciliation Act of 2010, in conjunction with the Patient Protection and Affordable Care Act, established a 2.3% excise tax on medical devices sold domestically beginning on January 1, 2013. The Company included the cost of MDET in cost of product revenue during the years ended December 31, 2015, 2014 and 2013, net of amounts directly billed to the customer for this tax, if any. Deferred Commissions Deferred commissions are the direct and incremental costs directly associated with the MRIdian system contracts with customers, which primarily consist of sales commissions to our direct sales force. The commissions are deferred and expensed in proportion to the revenue recognized upon the acceptance of the MRIdian system. At December 31, 2015 and 2014, the Company had $799 thousand and $221 thousand deferred commissions recorded as part of prepaid expenses and other current assets on the accompanying consolidated balance sheets. Income Taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities. Valuation allowances are established when necessary to reduce deferred tax assets where, based upon the available evidence, management concludes that it is more-likely-than not that the deferred tax assets will not be realized. Because of the uncertainty of the realization of the deferred tax assets, the Company has recorded a full valuation allowance against its net deferred tax assets. In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. In the event the Company was to determine that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, it would make an adjustment to the valuation allowance which would reduce the provision for income taxes. Reserves are provided for tax benefits for which realization is uncertain. Such benefits are only recognized when the underlying tax position is considered more likely than not to be sustained on examination by a taxing authority, assuming they possess full knowledge of the position and facts. It is the Company’s policy to include any penalties and interest related to income taxes in its income tax provision; however, the Company currently has no penalties or interest related to income taxes. The earliest year that the Company is subject to examination is the year ended December 31, 2004. Convertible Preferred Stock Warrant Liability The Company’s warrant to purchase convertible preferred stock is classified as a liability on the consolidated balance sheets at fair value upon issuance because the warrant is exercisable for contingently redeemable preferred stock which is classified outside of stockholders’ deficit. The warrant is subject to re-measurement to fair value at each balance sheet date, and any change in fair value is recognized in the consolidated statements of operations as other income (expense), net. In July 2015, upon the Merger of the Company and ViewRay Technologies, Inc., and the Private Placement, the convertible preferred stock warrants were converted into warrants to purchase the Company’s common stock, and the fair value of the preferred stock warrant liability was reclassified to additional paid-in capital. Net Loss per Share The Company’s basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. The net loss attributable to common stockholders was not allocated to the convertible preferred stock under the two-class method as the convertible preferred stock do not have a contractual obligation to share in the net loss attributable to common stockholders. The diluted net loss per share attributable to common stockholders is computed by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, convertible preferred stock, stock options, and warrants to purchase convertible preferred stock and common stock are considered to be common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is anti-dilutive. Recent Accounting Pronouncements In November 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2015-17, Balance Sheet Classification of Deferred Taxes, In July 2015, the FASB issued ASU 2015-11, Simplifying the Measurement of Inventory In April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40), In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842)

Merger

Merger	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Merger	3 . Merger On July 23, 2015, ViewRay, Inc. (f/k/a Mirax Corp.), or the Company, and ViewRay Technologies, Inc. (f/k/a ViewRay Incorporated), consummated an Agreement and Plan of Merger and Reorganization, or Merger Agreement. Pursuant to the Merger Agreement, the stockholders of ViewRay Technologies, Inc. contributed all of their equity interests to the Company for shares of the Company’s common stock and merged with the Company’s subsidiary, which resulted in ViewRay Technologies, Inc. becoming a wholly-owned subsidiary of the Company, or the Merger. Effective as of July 23, 2015, the Company amended and restated its Certificate of Incorporation to increase its authorized common stock to 300,000,000 shares and 10,000,000 shares of “blank check” preferred stock, par value of $0.01 per share. Upon the closing of the Merger, under the terms of the Split-Off Agreement, dated July 23, 2015 among the Company, ViewRay Technologies, Inc. and Vesuvius Acquisition Sub, Inc., the acquisition subsidiary of the Company, or the Split-Off Agreement, and a general release agreement dated July 23, 2015, or the General Release Agreement, the Company transferred all of its pre-Merger operating assets and liabilities to wholly- owned special-purpose subsidiary incorporated in Nevada, Vesuvius Acquisition Sub, Inc. or the Split-Off Subsidiary. Thereafter, the Company transferred all of the outstanding shares of capital stock of the Split-Off Subsidiary to certain pre-Merger insiders of the Company in exchange for the surrender and cancellation of shares of the Company’s common stock held by such persons. Together with the Merger, on July 23, 2015, ViewRay Technologies, Inc. effected a 2.975-for-1 stock split of its then outstanding common stock and convertible preferred stock, collectively referred to as Capital Stock, and convertible preferred stock warrants, in which (i) each share of outstanding Capital Stock was increased into 2.975 shares of Capital Stock; (ii) the number of outstanding options to purchase each Capital Stock was proportionately increased on a 2.975-for-1 basis; (iii) number of shares reserved for future option grants under the 2008 Plan were proportionately increased on a 2.975-for-1 basis; (iv) the exercise price of each such outstanding option was proportionately decreased on a 2.975-for-1 basis; and (v) each share of outstanding convertible preferred stock warrant was increased into 2.975 shares of convertible preferred stock warrant. All of the share and per share amounts have been adjusted, on a retroactive basis, to reflect this 2.975-for-1 stock split. At the closing of the Merger, the Company conducted a private placement offering, or the Private Placement, of its securities for $26.3 million, net of offering cost, through the sale of 5,884,504 shares of the common stock of the surviving corporation, at an offering price of $5.00 per share. Investors in ViewRay Technologies, Inc. purchased $17.0 million of shares in the Private Placement. Certain shareholders of the Company retained, after giving effect to the Split-Off, 1,000,005 shares of the common stock of the surviving corporation upon the Private Placement. The former stockholders of ViewRay Technologies Inc. collectively own approximately 90.9% of the outstanding shares of the Company’s common stock. Immediately following the closing of the Merger, the Company’s outstanding shares of common stock (on a fully diluted basis) are owned as follows: · Former holders of the ViewRay Technologies, Inc.’s capital stock hold an aggregate of 34,715,582 shares of the Company’s common stock, or approximately 72.7% on a fully diluted basis; · The Private Placement, resulted in an aggregate of 5,884,504 shares of the Company’s common stock, consisting of 3,400,003 shares held by ViewRay Technologies, Inc. shareholders and 2,484,501 shares issued to new shareholders, or together approximately 12.3% on a fully diluted basis; · 128,231 shares of ViewRay Technologies, Inc.’s preferred stock warrant were converted to the Company’s common stock warrant, or approximately 0.3% on a fully diluted basis; · 198,760 shares of common stock issued as warrants to placement agents as payment for services provided, or approximately 0.4% on a fully diluted basis; · Holders of the Company’s common stock prior to the closing of the Merger hold an aggregate of 1,000,005 shares of the Company’s common stock, or approximately 2.1% on a fully diluted basis; and · 9,225,397 shares of common stock are reserved for issuance under the 2008 Stock Incentive Plan, or the 2008 Plan, and the 2015 Equity Incentive Plan of ViewRay, or the 2015 Plan, collectively representing approximately 19.3% on a fully diluted basis. Upon closing, 1,507,147 options to purchase shares of the Company’s common stock are granted to employees under the 2015 Plan. In addition, the Board of Directors of the Company has adopted a 285,621-share reserve under the 2015 ESPP. The Merger is being accounted for as a reverse-merger and recapitalization. ViewRay Technologies, Inc. is the acquirer for financial reporting purposes, and ViewRay, Inc. is the acquired company under the acquisition method of accounting in accordance with FASB ASC Topic 805, Business Combination. Consequently, the assets, liabilities and operations that will be reflected in the historical consolidated financial statements prior to the Merger will be those of ViewRay Technologies, Inc. and will be recorded at the historical cost basis, and the consolidated financial statements after completion of the Merger will include the assets, liabilities and results of operations of ViewRay Technologies, Inc. up to the day prior to the closing of the Merger and the assets, liabilities and results of operations of the combined company from and after the closing date of the Merger.

Balance Sheet Components

Balance Sheet Components	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Balance Sheet Components	4 . Balance Sheet Components Property and Equipment Property and equipment consisted of the following (in thousands): December 31 2015 2014 Prototype $ 6,492 $ 6,342 Machine and equipment 7,128 4,214 Leasehold improvements 1,532 1,270 Furniture and fixtures 350 263 Software 832 647 Construction in progress 1,851 — Property and equipment, gross 18,185 12,736 Less: accumulated depreciation and amortization (10,879 ) (9,805 ) Property and equipment, net $ 7,306 $ 2,931 Depreciation and amortization expense related to property and equipment was $1.1 million, $853 thousand and $1.1 million during the years ended December 31, 2015, 2014 and 2013, respectively. Intangible Assets Intangible assets consisted of the following (in thousands): December 31 2015 2014 License cost $ 500 $ 500 Patents 104 — Intangible assets, gross $ 604 $ 500 Accumulated amortization (404 ) (236 ) Intangible assets, net $ 200 $ 264 Intangible amortization expense was $168 thousand, $167 thousand and $69 thousand during the years ended December 31, 2015, 2014 and 2013, respectively, which were recorded in general and administrative expenses in the consolidated statements of operations. At December 31, 2015, the estimated future amortization expense of purchased intangible assets was as follows (in thousands): Year Ended December 31, Estimated Amortization Expense 2016 $ 115 2017 18 2018 18 2019 18 2020 18 Thereafter 13 Total amortization expense $ 200 Accrued Liabilities Accrued liabilities consisted of the following (in thousands): December 31 2015 2014 Accrued payroll and related benefits $ 1,938 $ 1,652 Accrued accounts payable 1,880 143 Sales tax and medical device excise tax payable 219 499 Accrued legal and accounting 857 901 Accrued interest — 142 Other 519 296 Total accrued liabilities $ 5,413 $ 3,633 Deferred Revenue Deferred revenue consisted of the following (in thousands): December 31 2015 2014 Deferred revenue: Product $ 5,050 $ 6,919 Services 911 442 Total deferred revenue 5,961 7,361 Less: current portion of deferred revenue (5,616 ) (7,361 ) Noncurrent portion of deferred revenue $ 345 $ —

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	5 . Fair Value of Financial Instruments Assets and liabilities recorded at fair value on a recurring basis in the balance sheets are categorized based upon the level of judgment associated with the inputs used to measure their fair values. Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. Valuation techniques used to measure fair value must maximize the use of observable inputs and minimize the use of unobservable inputs. The standard describes a fair value hierarchy based on three levels of inputs, of which the first two are considered observable and the last unobservable, that may be used to measure fair value which are the following: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 2—Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The assets’ or liabilities’ fair value measurement level within the fair value hierarchy is based on the lowest level of any input that is significant to the fair value measurement. The Company’s financial instruments that are carried at fair value mainly consist of Level 1 assets and Level 3 liabilities. Level 1 assets include highly liquid bank deposits and money market funds, which were not material at December 31, 2015 or 2014. Level 3 liabilities that are measured on a recurring basis include convertible preferred stock warrant liabilities. The convertible preferred stock warrant liability was valued using the Black-Scholes option-pricing model. Generally, increases (decreases) in the fair value of the underlying stock and estimated term would result in a directionally similar impact to the fair value of the warrant (see Note 13). The convertible preferred stock warrants were issued in December 2013 and were outstanding at December 31, 2014. In July 2015, upon the Merger of the Company and ViewRay Technologies, Inc., and the Private Placement, the convertible preferred stock warrants were converted into warrants to purchase the Company’s common stock. The aggregate fair value of these warrants upon the closing of the Merger is $93 thousand which was reclassified from liabilities to additional paid-in-capital, and the Company no longer recorded change in fair value adjustments. The following table sets forth the fair value of the Company’s financial liabilities by level within the fair value hierarchy (in thousands): At December 31, 2014 Level 1 Level 2 Level 3 Total Convertible preferred stock warrant liability $ — $ — $ 138 $ 138 The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial liabilities (in thousands): Year Ended December 31, 2015 2014 2013 Fair value, beginning of period $ 138 $ 158 $ — Issuance of convertible preferred stock warrant — — 158 Change in fair value of Level 3 financial liabilities (45 ) (20 ) — Fair value, end of period $ 93 $ 138 $ 158 The gains and losses from re-measurement of Level 3 financial liabilities are recorded as part of other income (expense), net in the consolidated statements of operations.

Debt

Debt	12 Months Ended
	Dec. 31, 2015
Debt Instruments [Abstract]
Debt	6 . Debt Hercules Term Loan In December 2013, ViewRay Technologies, Inc. entered into a Loan and Security Agreement, or the Hercules Term Loan, with Hercules Technology Growth Capital, Inc. and Hercules Technology III, L.P., or together, Hercules, for $15.0 million that was outstanding at December 31, 2014. Borrowings under the Hercules Term Loan bear cash interest at the greater of the annual prime rate plus 7.0% or 10.25%, which was 10.25% at December 31, 2014. In addition, borrowings under the Hercules Term Loan bear deferred payment in-kind interest at 1.5% per annum. Interest only payments began in January 2014, with monthly principal and interest payments beginning on January 1, 2015 and the entire balance of the Hercules Term Loan are to be paid in full by the June 1, 2017 maturity date. The Hercules Term Loan is subject to a prepayment penalty of 5% on the outstanding balance during the first 12 months following the funding of the loan and 1% on the outstanding balance thereafter until maturity. The Hercules Term Loan was issued at a discount of $466 thousand, which was amortized to interest expense during the life of the loan using the effective interest method. The discount included the fair value of a convertible preferred stock warrant that was issued with the Hercules Term Loan, as discussed in the following paragraph, and the related transaction costs. The Hercules Term Loan is collateralized by essentially all the assets of ViewRay Technologies, Inc. and limits its ability with respect to additional indebtedness, investments or dividends, among other things, subject to customary exceptions. In connection with the issuance of the Hercules Term Loan, ViewRay Technologies, Inc. entered into a Warrant Agreement with Hercules to issue a fully vested and exercisable warrant to purchase 128,231 shares of Series C convertible preferred stock with an exercise price of $5.84 per share. The warrant is exercisable any time before the later of 10 years from issuance or five years after an IPO. The warrant provides for anti-dilution rights on the Series C convertible preferred stock, which includes one-time down-round protection. The fair value of the warrant upon issuance of $158 thousand was recorded as convertible preferred stock warrant liability and a discount to the carrying value of the Hercules Term Loan. The fair value of the warrant at the time of issuance was estimated using the Black-Scholes option-pricing model with the following assumptions: expected term of two years, expected volatility of 30%, risk-free interest rate of 0.4% and expected dividend yield of 0%. See Note 13 for assumptions used to estimate the fair value of convertible preferred stock warrant liability upon conversion into warrants to purchase common stock and at December 31, 2014. In June 2015, ViewRay Technologies, Inc. paid off in full the outstanding balances on Hercules Term Loan, including the related interest and other penalty fee, using part of the proceeds received from the CRG Term Loan discussed below. CRG Term Loan In June 2015, ViewRay Technologies, Inc. entered into a Term Loan Agreement, or the CRG Term Loan, with Capital Royalty Partners II L.P., Capital Royalty Partners II – Parallel Fund “A” L.P., Capital Royalty Partners II (Cayman) L.P. and Parallel Investment Opportunities Partners II L.P. or together with their successors by assignment, CRG, for up to $50.0 million of which $30.0 million was available immediately upon closing, and the remaining $20.0 million was available on or before June 26, 2016 at its option upon the occurrence of either (i) an initial public offering of its common stock on a nationally recognized securities exchange that raises a minimum of $40.0 million in net cash proceeds with a minimum of $120.0 million post money valuation, or Qualifying IPO, or (ii) achievement of a minimum of $25.0 million of aggregate product and service revenue during any consecutive 12 months before March 31, 2016. The Company drew down the first $30.0 million on closing date. The CRG Term Loan has a maturity date of June 26, 2020 and bears interest at a rate of 12.5% per annum to be paid quarterly during the interest-payment-only period of three years. The interest-payment-only period can be extended for another year until June 26, 2019 if the Company completes a Qualifying IPO on or before June 26, 2018. During the interest-payment-only period, the Company has the option to elect to pay only 8% of the 12.5% per annum interest in cash, and the remaining 4.5% of the 12.5% per annum interest as compounded interest, or deferred payment in-kind interest, added to the aggregate principal amount of the CRG Term Loan. Principal payment and any deferred payment in-kind interest is paid quarterly in equal installments following the end of the interest-payment-only period through maturity date. On March 24, 2016, the Company and CRG executed an amendment to the original terms of the CRG Term Loan such that, with regard to the conditions for borrowing the remaining $20.0 million available under the CRG Term Loan, the Company may, at its election, draw down (i) an amount of either $10.0 million or $15.0 million in up to two advances upon achievement of a minimum of $15.0 million of aggregate product and service revenue during any consecutive 12 month period ending on or before March 31, 2016 and (ii) an additional $5.0 million (or $10.0 million, if the previous draw made was only in an amount of $10.0 million) upon achievement of a minimum of $25.0 million of aggregate product and service revenue during any consecutive 12 month period ending on or before December 31, 2016 and upon execution of the first sales contract of the Company’s second generation product. On March 21, 2016, the Company achieved the minimum of $15.0 million gross revenue requirement which makes the first $15.0 million of the remaining $20.0 million immediately available for draw down by the Company. The CRG Term Loan is subject to a prepayment penalty of 3% on the outstanding balance during the first 12 months following the funding of the loan, 2% on the outstanding balance after year 1 but on or before year 2, 1% on the outstanding balance after year 2 but on or before year 3, and 0% on the outstanding loan if prepaid after year 3 thereafter until maturity. The CRG Term Loan is also subject to a facility fee of 7% based on the sum of the amount drawn and any outstanding payment in-kind interest payable on the maturity date or the date such loan becomes due. All direct issuance costs were accounted for as a discount on the CRG Term Loan and will be amortized to interest expense during the life of the loan using the effective interest method. The CRG Term Loan is subject to financial covenants and is collateralized by essentially all assets of the Company and limits its ability with respect to additional indebtedness, investments or dividends, among other things, subject to customary exceptions. The Company’s scheduled future payment on the CRG Term Loan at December 31, 2015 are as follows (in thousands): Year Ended December 31, 2016 $ 2,541 2017 2,652 2018 12,019 2019 19,644 2020 and thereafter 10,506 Total future payments $ 47,362 Less: amount representing interest and end-of-term facility fee (17,362 ) Total principal amount 30,000 Less: unamortized debt discount (984 ) Carrying value of long-term debt $ 29,016 Less: current portion — Long-term portion $ 29,016 2014 Convertible Promissory Notes In August 2014, the Company entered into a Convertible Promissory Note Agreement, or the Convertible Note Agreement, with a majority of its current investors to sell convertible promissory notes in an aggregate principal amount of $10.0 million with the option to raise an additional $1.5 million, or 2014 Notes. The Company received gross proceeds of $3.9 million in August 2014 and $6.1 million in November 2014 under the Convertible Note Agreement. The 2014 Notes carried a simple interest rate of 8% per annum and were subordinated in right of payment to all of the Company’s other indebtedness. The 2014 Notes were to mature in November 2015 unless previously converted. The Convertible Note Agreement provided for the conversion of the 2014 Notes at the option of the majority investors, and at any time, into shares of Series C convertible preferred stock at the then applicable conversion price. In December 2014, the holders of the 2014 Notes opted to convert the outstanding principal and accrued interest of $10.2 million into 1,739,405 shares of Series C convertible preferred stock at a price of $5.84 per share in accordance with the terms of the Convertible Note Agreement. As of December 31, 2014, the 2014 Notes are no longer outstanding. In addition, the option to raise an additional $1.5 million under the Convertible Note Agreement expired unexercised in December 2014 and no more 2014 Notes will be issued under this agreement.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	7 . Commitments and Contingencies Operating Leases The Company leases office space in Oakwood Village, Ohio and Mountain View, California under non-cancellable operating leases. At December 31, 2015, the future minimum payments for the operating leases are as follows (in thousands): Year Ended December 31, 2016 $ 1,113 2017 1,106 2018 963 2019 823 Total future minimum payments $ 4,005 Rent expense incurred under operating leases was $1.3 million, $683 thousand and $308 thousand during the years ended December 31, 2015, 2014 and 2013, respectively. Contingencies The Company is subject to claims and assessments from time to time in the ordinary course of business. The Company records a provision for a liability when it believes that it is both probable that a liability has been incurred and the amount can be reasonably estimated. Significant judgment is required to determine both probability and the estimated amount. In the normal course of business, the Company may become involved in legal proceedings. The Company will accrue a liability for such matters when it is probable that a liability has been incurred and the amount can be reasonably estimated. When only a range of possible loss can be established, the most probable amount in the range is accrued. If no amount within this range is a better estimate than any other amount within the range, the minimum amount in the range is accrued. The accrual for a litigation loss contingency might include, for example, estimates of potential damages, outside legal fees and other directly related costs expected to be incurred. At December 31, 2015, the Company was not involved in any material legal proceedings. Purchase Commitments At December 31, 2015 and 2014, the Company had no outstanding firm purchase commitments.

License Agreement

License Agreement	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
License Agreement	8 . Licensing Agreement In December 2004, ViewRay Technologies, Inc. entered into a licensing agreement with the University of Florida Research Foundation, Inc., or UFRF, whereby UFRF granted the Company a worldwide exclusive license to certain of UFRF’s patents in exchange for 33,652 shares of common stock and a royalty from sales of products developed and sold by the Company utilizing the licensed patents. ViewRay Technologies, Inc. met all of the product development and commercialization milestones at December 31, 2013 and started to make quarterly royalty payments in 2014. Royalty payments are based on 1% of net sales, defined as the amount collected on sales of licensed products and/or licensed processes after deducting trade and/or quantity discounts, credits on returns and allowances, outbound transportation costs paid and sales tax. Minimum quarterly royalty payments of $50 thousand commenced with the quarter ended March 31, 2014 and are payable in advance. Minimum royalties paid in any calendar year will be credited against earned royalties for such calendar year. The royalty payments continue until the earlier of (i) the date that no licensed patents remain enforceable or (ii) the payment of earned royalties, once begun in 2014, cease for more than four consecutive calendars quarters. Royalty expenses based on 1% of net sales were $102 thousand, $137 thousand and $26 thousand during the years ended December 31, 2015, 2014 and 2013, respectively, and were recorded as product cost of revenue in the accompanying consolidated statements of operations. The minimum royalty payments in excess of 1% of net sales were $49 thousand, $63 thousand and nil during the years ended December 31, 2015, 2014 and 2013, respectively, and were recorded as general and administrative expenses in the accompanying consolidated statements of operations.

Grant Revenue

Grant Revenue	12 Months Ended
	Dec. 31, 2015
Text Block [Abstract]
Grant Revenue	9 . Grant Revenue In December 2008, ViewRay Technologies, Inc. entered into an agreement with the county redevelopment fund in the State of Ohio for a loan of up to $800 thousand to fund the renovation of its headquarters. The loan, which bore interest at 6% annually through the maturity date of December 31, 2009, is secured by the Company’s leasehold improvements. Under the terms of the loan agreement, the lender may forgive $240 thousand if the Company meets certain permanent job creation requirements within the State of Ohio. In July 2010, $560 thousand of principal and accrued interest through the loan maturity date were repaid. In September 2015, the remaining $240 thousand was forgiven and was recognized as grant revenue during the year ended December 31, 2015. In April 2009, the Company and other collaborators were awarded a grant from the State of Ohio of up to $5.0 million in total support pursuant to the Third Frontier Biomedical Research Commercialization Program. The Company’s portion of this grant is $2.8 million. Consistent with the grant agreement, the funds become due to the Company upon written request to the grantor subsequent to the achievement of milestone and qualifying expenditures being incurred. The terms of the grant obligate the Company to develop and commercialize MRIdian primarily at its headquarters in the State of Ohio, to raise certain amounts of new equity investment and to incur certain levels of expenditures to develop and market MRIdian. The grant revenue from this arrangement was recognized as these milestones were achieved before the arrangement expired in April 2013. The Company recorded grant revenue of $894 thousand during the year ended December 31, 2013.

Distribution Agreement

Distribution Agreement	12 Months Ended
	Dec. 31, 2015
Other Industries [Abstract]
Distribution Agreement	10 . Distribution Agreement In December 2014, ViewRay Technologies, Inc. entered into a distribution agreement with Itochu Corporation, or Itochu, a Japanese entity, pursuant to which the Company appointed Itochu as its exclusive distributor for the sale and delivery of its MRIdian products within Japan. In consideration of the exclusive distribution rights granted, ltochu agreed to pay a distribution fee of $4.0 million in three installments: (i) the first installment of $1.0 million was due upon execution of the distribution agreement; (ii) the second installment of $1.0 million is due within 10 business days following submission of the application for regulatory approval of the Company’s product to the Japan regulatory authority; and (iii) the final installment of $2.0 million is due within 10 business days following receipt of approval for the Company’s product from the Japan regulatory authority. The distribution fee paid by Itochu is refundable if the Company fails to obtain the approval from the Japan regulatory authority before December 31, 2017. The Company received the first installment of $1.0 million in December 2014 and the second installment of $1.0 million in December 2015. Both amounts were recorded as customer deposits in the accompanying consolidated balance sheets. The exclusive distribution agreement has an initial term of 10 years, and contains features customary in such distribution agreements. Under this distribution agreement, the Company will supply its products and services to Itochu based upon the Company’s then-current pricing. In conjunction with the distribution agreement, Itochu also purchased $5.2 million of Series C convertible preferred stock in December 2014 at a price of $5.84 per share and became a stockholder of the Company (see Note 12).

Common Stock Reserved for Issua

Common Stock Reserved for Issuance	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Common Stock Reserved for Issuance	11 . Common Stock Reserved for Issuance The common stock reserved for future issuance at December 31, 2015 and 2014 was as follows: December 31 2015 2014 Conversion of outstanding convertible preferred stock — 27,654,928 Shares underlying outstanding stock options 6,053,672 4,248,504 Shares available for future stock option grants 3,166,968 295,101 ESPP shares available for issuance 285,621 — Warrant to purchase convertible preferred stock — 128,231 Warrant to purchase common stock 326,991 — Total shares of common stock reserved 9,833,252 32,326,764

Convertible Preferred Stock

Convertible Preferred Stock	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Convertible Preferred Stock	12 . Convertible Preferred Stock In February 2013, the Company raised $5.0 million through the sale and issuance of 983,558 shares of Series D-1 convertible preferred stock for $5.08 per share. Recapitalization In May and June 2013, the Company effected a recapitalization in connection with a Series D-2 convertible preferred stock financing, or the Series D-2 Offering. The Series D-2 Offering consisted of (i) the sale and issuance of 3,013,797 shares of Series D-2 convertible preferred stock for $15.3 million, or $5.08 per share, and (ii) the issuance of 3,196,417 shares of Series D-2 convertible preferred stock to participating investors in exchange for all then-outstanding dividends accrued on shares of Series B-1, Series C and Series D-1 convertible preferred stock at an exchange rate equal to the sales price of the Series D-2 Offering of $5.08 per share. Non-participating holders of 1,470,485 shares of Series C convertible preferred stock received 147,051 shares of common stock, on a 10:1 basis, in exchange for these shares and accrued dividends of $1.4 million, or the Non-participating Exchange. At the closing of the Series D-2 Offering, all then-outstanding shares of Senior Convertible Preferred Stock (defined as all outstanding shares of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock) were exchanged for an equal number of newly-issued shares of Series B convertible preferred stock, or the Participating Exchange, containing substantially similar rights to those contained in the Senior Convertible Preferred Stock except that (i) rights to dividends are no longer cumulative and therefore dividends accrue to holders of Series B convertible preferred stock only when declared and (ii) the liquidation preference for the prior shares of Series B-1 convertible preferred stock was increased. All shares of Senior Convertible Preferred Stock were surrendered and cancelled after the recapitalization. The recapitalization was accounted for as an extinguishment of the Senior Convertible Preferred Stock which resulted in the following: • For the Non-participating Exchange, the Company recognized a gain on extinguishment of Series C convertible preferred stock in the amount $8.8 million as the difference between the carrying value of the securities surrendered (i.e., carrying value of non-participating Series C convertible preferred stock and the related accrued dividends) and the fair value of the common stock issued in exchange. The $8.8 million gain was a deemed capital contribution to the holders of the common stock that was recognized as a decrease to net loss attributable to common stockholders and a decrease to accumulated deficit. • For the Participating Exchange, the Company recognized a charge on extinguishment of participating Senior Convertible Preferred Stock as the difference between the carrying value of the securities surrendered (i.e., carrying value of the participating Senior Convertible Preferred Stock) and the fair value of the Series B convertible preferred stock issued in exchange. The $6.9 million charge was a deemed dividend that was recognized as an increase to net loss attributable to common stockholders and an increase to accumulated deficit. In November 2013, the Company raised $15.0 million through the sale and issuance of 2,564,638 shares of Series C convertible preferred stock for $5.84 per share. In December 2014, the Company issued 2,619,951 shares of Series C convertible preferred stock, consisting of (i) the issuance of 880,546 shares for $5.2 million, or $5.84 per share, to Itochu in conjunction with the distribution agreement, and (ii) the issuance of 1,739,405 shares upon conversion of the outstanding principal and accrued interest of the 2014 Notes (see Note 6). In January 2015, the Company issued an aggregate of 162,407 shares of Series C convertible preferred stock to a new investor at a price of $5.84 per share for a total gross consideration of $950 thousand. In February 2015, the Company issued 2,564,652 shares of Series C convertible preferred stock to another investor at a price of $5.84 per share for total gross consideration of $15.0 million. On July 23, 2015, upon the closing of the Merger, all of ViewRay Technologies, Inc.’s 30,381,987 shares of outstanding convertible preferred stock were converted into the Company’s common stock at a 1:1 conversion rate. The changes in the shares of convertible preferred stock and common stock during the years ended December 31, 2015, 2014 and 2013 were as follows: Series A Convertible Preferred Stock Extinguished Series B-1 Convertible Preferred Stock Extinguished Series C Convertible Preferred Stock Extinguished Series D-1 Convertible Preferred Stock Extinguished Series D-2 Convertible Preferred Stock New Series B Convertible Preferred Stock New Series C Convertible Preferred Stock Total Convertible Preferred Stock Common Stock Balance at December 31, 2012 163,462 6,321,238 9,108,533 1,155,172 — — — 16,748,405 730,203 Issuance of Series D-1 convertible preferred stock — — — 983,558 — — — 983,558 — Issuance of Series D-2 convertible preferred stock — — — — 3,013,797 — — 3,013,797 — Conversion of Series C convertible preferred stock and related dividends dividends into common stock and deemed capital contribution — — (1,470,485 ) — — — — (1,470,485 ) 147,051 Conversion of accrued dividends into Series D-2 convertible preferred stock — — — — 3,196,417 — — 3,196,417 — Extinguishment of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock — (6,321,238 ) (7,638,048 ) (2,138,730 ) (6,210,214 ) — — (22,308,230 ) — Exchange of new Series B convertible preferred stock and deemed dividend — — — — — 22,308,230 — 22,308,230 — Issuance of new Series C convertible preferred stock — — — — — — 2,564,638 2,564,638 — Issuance of common stock from option exercise — — — — — — — — 1,463 Balance at December 31, 2013 163,462 — — — — 22,308,230 2,564,638 25,036,330 878,717 Repurchase of Series A convertible preferred stock and deemed capital contribution (1,353 ) — — — — — — (1,353 ) — Issuance of Series C convertible preferred stock — — — — — — 880,546 880,546 — Conversion of convertible promissory notes into Series C convertible preferred stock — — — — — — 1,739,405 1,739,405 — Issuance of common stock from option exercise — — — — — — — — 28,320 Balance at December 31, 2014 162,109 — — — — 22,308,230 5,184,589 27,654,928 907,037 Issuance of Series C convertible preferred stock — — — — — — 2,727,059 2,727,059 — Conversion of convertible preferred stock into common stock in connection with the merger (162,109 ) — — — — (22,308,230 ) (7,911,648 ) (30,381,987 ) 30,381,987 Issuance of common stock upon private placement — — — — — — — — 5,884,504 Issuance of common stock to Mirax — — — — — — — — 1,000,005 Issuance of common stock from option exercise — — — — — — — — 31,427 Balance at December 31, 2015 — — — — — — — — 38,204,960 Prior to the completion of the recapitalization in June 2013, the rights, privileges and preferences of Series A, Series B-1, Series C and Series D-1 convertible preferred stock were as follows: Voting Rights Each share of Series A, Series B-1, Series C and Series D-1 convertible preferred stock was entitled to voting rights equal to the number of shares of common stock into which each share could be converted. The shares possessed contain certain customary rights and protective provisions including anti-dilution protection, pre-emptive and protective rights in the event of future issuances of equity securities by the Company, rights to limit the ability of the Company to incur indebtedness without prior approval of a majority of the Series D-1 convertible preferred stock holders, registration rights in the event of a public offering of the Company’s common stock, right of first refusal and co-sale rights in the event of certain transfers of shares by or among shareholders, the ability of a majority of holders of convertible preferred stock to require the tender of all shares in the event of a sale of the Company and information rights. The Company’s board of directors consisted of 8 members. The holders of Series A, voting as a separate class, are entitled to elect one member of the board of directors. The holders of Series B-1, voting as a separate class, are entitled to elect seven members of the board of directors. The holders of Series C, voting as a separate class, are entitled to elect one member of the board of directors. The holders of common stock, voting as a separate class, are entitled to elect two members of the board of directors. Conversion Rights Each share of Series A, Series B-1, Series C and Series D-1 convertible preferred stock was convertible by any holder at any time into common stock. The conversion rate was determined by dividing the purchase price applicable to such shares of convertible preferred stock ($3.99 for Series A and Series B-1 and $5.08 for Series C and Series D-1 convertible preferred stock) by the conversion price ($3.99 for Series A and Series B-1 and $5.08 for Series C and Series D-1 convertible preferred stock). Conversion of such shares was automatic upon the closing of an underwritten public offering with proceeds equal to or exceeding $15.25 per share, and in which the net proceeds received by the Company equal or exceed $50.0 million or the affirmative vote of holders of shares of convertible preferred stock representing at least a majority of the voting power of the then outstanding shares of Series A, Series B-1, Series C and Series D-1 convertible preferred stock, voting together as a single class. Adjustment of Conversion Price for Qualifying Dilutive Issuances In the event the Company issued additional shares of common stock after the Series D-1 convertible preferred stock original issue date without consideration or for a consideration per share less than the conversion price in effect immediately prior to such issuance, then and in each such event the conversion price would have been reduced to a price equal to such conversion price multiplied by the following fraction: • the numerator of which is equal to the sum of (i) the product of the number of shares of common stock outstanding or deemed to be outstanding immediately prior to such issuance and the conversion price in effect immediately prior to such issuance) and (ii) the product of the number of additional shares of common stock so issued and the average price per share received by the Company for the additional shares of common stock so issued); and • the denominator of which is equal to the number of shares of common stock outstanding or deemed to be outstanding immediately prior to such issuance plus the number of additional shares of common stock so issued. Dividends Holders of Series B-1, Series C and Series D-1 convertible preferred stock, in preference to the holders of Series A convertible preferred stock and common stock, were entitled to receive cash dividends at the per annum rate of 8% of the convertible preferred stock purchase price. Such payments were to be paid in order of preference (Series D-1, Series C, Series B-1 convertible preferred stock). Dividends were cumulative from the date of issuance of the respective convertible preferred stock until paid. Holders of Series B-1 convertible preferred stock were entitled to receive, when, as and if declared by the board of directors, cash dividends at the per annum rate of 8% of the Series B-1 convertible preferred stock original issue price of $3.99 per share and such dividend was cumulative. Holders of Series C and Series D-1 convertible preferred stock were entitled to receive, when, as and if declared by the board of directors, cash dividends at the per annum rate of 8% of the Series C and Series D-1 convertible preferred stock original issue price of $5.08 per share and such dividend was cumulative. So long as 20% of the Series D-1 convertible preferred stock remained outstanding, the Company would not pay or declare any dividend on shares other than Series D-1 convertible preferred stock without the consent of the Series D-1 convertible preferred stockholders. In the event dividends were paid on any share of common stock, the Company would have paid an additional dividend on all outstanding shares of Series A, Series B-1, Series C and Series D-1 convertible preferred stock in a per share amount equal (on an as-if-converted-to-common-stock-basis) to the amount paid or set aside for each share of common stock. Liquidation Preferences Upon any liquidation, dissolution or winding-up of the Company, whether voluntary or involuntary, or a corporate organization, the holders of Series B-1, Series C and Series D-1 convertible preferred stock were entitled to be paid out of Company assets before any payment was to be made to the holders of Series A convertible preferred stock and common stock. Holders of Series A convertible preferred stock were entitled to be paid out of any remaining assets in the event of a liquidation event before any payment was to be made to the holders of common stock. Upon the completion of distributions required to satisfy the convertible preferred stock liquidation preferences, any remaining assets were to be distributed pro rata among the holders of convertible preferred stock and common stock, treating all convertible preferred stock as if it were converted to common stock. The Series C and D-1 convertible preferred stock liquidation preference was equal to the sum of $5.08 per share plus any accrued but unpaid dividends, whether or not declared and any declared but unpaid dividends on such shares. The Series B-1 convertible preferred stock liquidation preference was equal to the sum of $3.99 per share plus any declared but unpaid dividends on such shares. The Series A convertible preferred stock liquidation preference was $18.52 per share plus any declared but unpaid dividends on such shares. The liquidation preference of the convertible preferred stock was subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other recapitalization affecting such shares. Redemption The Series A, Series B-1, Series C and Series D-1 convertible preferred stock was not redeemable at the option of the holder. The convertible preferred stock was classified outside of stockholders’ deficit because, in the event of certain “liquidation events” that are not solely within the Company’s control (including a dissolution, change of control, acquisition, asset sale or winding up of the Company), the shares would become redeemable at the option of the holders. The Company did not adjust the carrying values of the convertible preferred stock to the deemed liquidation values of such shares since a liquidation event was not probable at any of the balance sheet dates. Subsequent adjustments to increase or decrease the carrying values to the ultimate liquidation values will be made only if and when it becomes probable that such a liquidation event will occur. Convertible preferred stock as of December 31, 2015 and 2014 consisted of the following (in thousands, except share data): December 31, 2015 Shares Authorized Shares Issued and Outstanding Aggregate Liquidation Preference Net Carrying Value Series A 398,500 — $ — $ — Series B 60,500,000 — — — Series C 19,812,497 — — — Total 80,710,997 $ — $ — $ — December 31, 2014 Shares Authorized Shares Issued and Outstanding Aggregate Liquidation Preference Net Carrying Value Series A 398,500 162,109 $ 3,004 $ 3,003 Series B 60,500,000 22,308,230 113,405 112,080 Series C 13,562,497 5,184,589 30,323 30,027 Total 74,460,997 27,654,928 $ 146,732 $ 145,110 The rights, privileges and preferences of Series A, Series B and Series C convertible preferred stock (collectively, convertible preferred stock) at December 31, 2014 were as follows: Voting Rights Each share of convertible preferred stock is entitled to voting rights equal to the number of shares of common stock into which each share can be converted. The convertible preferred stock terms contain certain customary rights and protective provisions including anti-dilution protection, pre-emptive and protective rights in the event of future issuances of equity securities by the Company, rights to limit the ability of the Company to incur indebtedness without prior approval of a majority of the convertible preferred stock holders, registration rights in the event of a public offering of the Company’s common stock, right of first refusal and co-sale rights in the event of certain transfers of shares by or among shareholders, the ability of a majority of holders of convertible preferred stock to require the tender of all shares in the event of a sale of the Company and information rights. The Company’s board of directors consists of 10 members. The holders of Series A convertible preferred stock, voting as a separate class, are entitled to elect one member of the board of directors. The holders of Series B convertible preferred stock, voting as a separate class, are entitled to elect eight members of the board of directors. The holders of Series C convertible preferred stock, voting as a separate class, are entitled to elect one member of the board of directors. The holders of common stock, voting as a separate class, are entitled to elect two member of the board of directors. Conversion Rights Each share of convertible preferred stock is convertible by any holder at any time into common stock. The conversion rate is determined by dividing the purchase price applicable to such shares of convertible preferred stock ($3.99 for Series A, $5.08 for Series B and $5.84 for Series C convertible preferred stock) by the conversion price ($3.99 for Series A, $5.08 for Series B and $5.84 for Series C convertible preferred stock). Conversion of convertible preferred stock is automatic upon the closing of an underwritten public offering with proceeds equal to or exceeding $17.55 per share, and in which the net proceeds received by the Company equal or exceed $50.0 million or the affirmative vote of holders of shares of convertible preferred stock representing at least a majority of the voting power of the then outstanding shares of Series A, Series B and Series C convertible preferred stock, voting together as a single class. Adjustment of Conversion Price for Qualifying Dilutive Issuances In the event the Company issues additional shares of common stock after the Series C convertible preferred stock original issue date without consideration or for a consideration per share less than the conversion price in effect immediately prior to such issuance, then and in each such event the conversion price will be reduced to a price equal to such conversion price multiplied by the following fraction: • the numerator of which is equal to the sum of (i) the product of the number of shares of common stock outstanding or deemed to be outstanding immediately prior to such issuance and the conversion price in effect immediately prior to such issuance, and (ii) the product of the number of additional shares of common stock so issued and the average price per share received by the Company for the additional shares of common stock so issued); and • the denominator of which is equal to the number of shares of common stock outstanding or deemed to be outstanding immediately prior to such issuance plus the number of additional shares of common stock so issued. Dividends Holders of Series B and Series C convertible preferred stock, in preference to the holders of Series A convertible preferred stock and common stock, are entitled to receive, when, as and if declared by the board of directors, cash dividends at the per annum rate of 8% of the convertible preferred stock purchase price and such dividend is noncumulative. Holders of Series B convertible preferred stock are entitled to receive, when, as and if declared by the board of directors, cash dividends at the per annum rate of 8% of the Series B convertible preferred stock original issue price of $5.08 per share. Holders of Series C convertible preferred stock are entitled to receive, when, as and if declared by the board of directors, cash dividends at the per annum rate of 8% of the Series C convertible preferred stock original issue price of $5.84 per share and such dividend is noncumulative. So long as any senior shares of convertible preferred stock are outstanding, the Company will not pay or declare any dividend on Series A convertible preferred stock or common stock until all dividends on the Series B and Series C convertible preferred stock have been declared and paid. In the event dividends are paid on any share of Series A convertible preferred stock or common stock, the Company will pay an additional dividend on all outstanding shares of convertible preferred stock in a per share amount equal (on an as-if-converted-to-common-stock-basis) to the amount paid or set aside for each share of common stock. Liquidation Preferences Upon any liquidation, dissolution or winding-up of the Company, whether voluntary or involuntary, or corporate reorganization, holders of Series B and Series C convertible preferred stock are entitled to be paid out of Company assets before any payment will be made to the holders of Series A convertible preferred stock and common stock. Holders of Series A convertible preferred stock are entitled to be paid out of any remaining assets in the event of a liquidation event before any payment will be made to the holders of common stock. Upon the completion of distributions required to satisfy the convertible preferred stock liquidation preferences, any remaining assets will be distributed pro rata among the holders of convertible preferred stock and common stock, treating all convertible preferred stock as if it were converted to common stock. The Series C convertible preferred stock liquidation preference is equal to the sum of $5.84 per share plus any declared but unpaid dividends on such shares. The Series B convertible preferred stock liquidation preference is equal to the sum of $5.08 per share plus any declared but unpaid dividends on such shares. The Series A convertible preferred stock liquidation preference is $18.52 per share plus any declared but unpaid dividends on such shares. The liquidation preference of the convertible preferred stock is subject to appropriate adjustment in the event of any stock dividend, stock split, combination or other recapitalization affecting such shares. Redemption The convertible preferred stock is not redeemable at the option of the holder. The convertible preferred stock was classified outside of stockholders’ deficit because, in the event of certain “liquidation events” that are not solely within the Company’s control (including a dissolution, change of control, acquisition, asset sale or winding up of the Company), the shares would become redeemable at the option of the holders. The Company did not adjust the carrying values of the convertible preferred stock to the deemed liquidation values of such shares since a liquidation event was not probable at any of the balance sheet dates. Subsequent adjustments to increase or decrease the carrying values to the ultimate liquidation values will be made only if and when it becomes probable that such a liquidation event will occur. The rights, privileges and preferences of the Series C convertible preferred stock issued in January and February 2015 are the same as the Series C convertible preferred stock outstanding as of December 31, 2014.

Warrants

Warrants	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Warrants	13 . Warrants In connection with a 2013 debt financing (see Note 6), the Company issued a warrant to purchase 128,231 shares of Series C convertible preferred stock. The convertible preferred stock warrant was recorded as a liability and is adjusted to fair value at each balance sheet date, with the change in fair value being recorded as a component of other income (expense), net in the consolidated statements of operations. Upon issuance, the fair value of the warrant was estimated to be $158 thousand. For the years ended December 31, 2015, 2014 and 2013, the Company recognized gain of $45 thousand, $20 thousand and nil related to the change in fair value of the warrants in the accompanying consolidated statements of operations. Upon the closing of the Merger on July 23, 2015, all shares of Series C convertible preferred stock were converted into common stock, and the warrant to purchase Series C convertible preferred stock was converted into the warrant to purchase 128,231 shares of the Company’s common stock. As a result, the fair value of the preferred stock warrant liability of $93 thousand was reclassified into additional paid-in capital. At December 31, 2015 and 2014, the warrant had not been exercised and was still outstanding. The Company used the Black-Scholes option-pricing model to estimate the fair value of the convertible preferred stock warrant with the following assumptions: Upon the Closing of the Merger on July 23, 2015 December 31, 2014 Common Stock Warrants: Expected term (in years) 5.0 5.3 Expected volatility (%) 31.8% 30.0% Risk-free interest rate (%) 1.7% 1.7% Expected dividend yield (%) 0% 0% In connection with the Merger and the Private Placement, in July and August 2015, the Company issued 198,760 shares of warrants to purchase common stock at an exercise price of $5.00 per share to private placement agents as payment for services provided. These placement warrants are exercisable at any time at the option of the holder until the five year anniversary of its date of issuance. The Company estimated the aggregate fair value of the placement warrants on issuance date to be $316 thousand which was recorded in additional paid-in capital as an offering cost against the total proceeds from the Private Placement. The placement warrants were accounted for as equity awards. The fair value of the placement warrants was valued at their grant dates using the Black-Scholes pricing model and the following weighted average assumptions: Upon Issuance Common Stock Warrants: Expected term (in years) 5.0 Expected volatility (%) 31.8% Risk-free interest rate (%) 1.6% Expected dividend yield (%) 0%

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Stock-Based Compensation	14 . Stock-Based Compensation The Company adopted 2008 Stock Option and Incentive Plan, or 2008 Plan, and 2015 Equity Incentive Award Plan, or 2015 Plan, to its employees, officers, directors, advisors and consultants. With the establishment of the 2015 Plan, the Company no longer grant stock options under the 2008 Plan, and the shares available for future grants under the 2008 Plan were transferred to the 2015 Plan. Only stock options were granted under the 2008 Plan. The 2015 Plan provides for the grant of stock and stock-based awards including stock options, nonqualified stock options, restricted stock awards, restricted stock units and stock appreciation rights. The purpose of the 2008 Plan and 2015 Plan is to promote the interests of the Company by providing the opportunity to purchase or receive shares or to receive compensation that is based upon appreciation in the value of the shares to eligible recipients in order to attract and retain employees and provide additional incentive to work to increase the value of shares and a stake in the future of the Company. Options granted may be either incentive stock options or nonstatutory stock options. Under the 2008 Plan, incentive stock options could only have been granted to employees with exercise prices of no less than the fair value of the common stock on the grant date and nonstatutory options may be granted to employees or consultants at exercise prices of no less than 85% of the fair value of the common stock on the grant date, as determined by the board of directors. Under the 2015 Plan, for both inventive stock options and nonstatutory options, the exercise price should not be less than the fair value of the common stock on the date of grant. Under both the 2008 Plan and the 2015 Plan, if, at the time of grant, the optionee owns stock representing more than 10% of the voting power of all classes of stock of the Company, a 10% shareholder, the exercise price must be at least 110% of the fair value of the common stock on the grant date as determined by the board of directors. Options become exercisable generally ratably over four years, and expire in 10 years from the date of grant, or five years from the date of grant for 10% shareholders. In July 2015, the Company adopted the 2015 Employee Stock Purchase Plan, or 2015 ESPP and 285,621 shares were reserved for issuance under the 2015 ESPP. At December 31, 2015, no shares have been issued under the 2015 ESPP. During 2008, the Company issued to an officer a stock option for 38,059 shares outside of the 2008 Plan with an exercise price of $0.80 per share which vested over three years. These options were unexercised and expired in September 2014. The compensation expense related to stock options outside of the 2008 Plan were insignificant during the year ended December 31, 2014 and 2013. A summary of the Company’s stock option activity and related information is as follows: Options Outstanding Shares Available for Grant Number of Stock Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual (Years) Aggregate Intrinsic Value (In thousands) Balance at January 1, 2013 306,097 1,907,644 $ 0.71 6.3 $ 28 Additional authorized 2,359,662 Granted (1,190,349 ) 1,190,349 0.70 Exercised (1,463 ) 0.68 Cancelled 372,957 (372,957 ) 0.69 Balance at December 31, 2013 1,848,367 2,723,573 0.71 7.7 $ 138 Granted (1,642,799 ) 1,642,799 0.84 Exercised — (28,320 ) 0.73 Cancelled 89,533 (89,533 ) 0.74 Balance at December 31, 2014 295,101 4,248,519 0.76 7.7 $ 8,343 Additional authorized 4,708,447 — Granted (1,975,673 ) 1,975,673 5.03 Exercised — (31,427 ) 0.76 Cancelled 139,093 (139,093 ) 1.46 Balance at December 31, 2015 3,166,968 6,053,672 $ 2.13 7.6 $ 20,605 Vested and exercisable at December 31, 2014 2,379,076 $ 0.72 6.8 $ 4,764 Vested and expected to vest at December 31, 2014 3,777,913 $ 0.78 7.5 $ 7,452 Vested and exercisable at December 31, 2015 3,179,361 $ 0.96 6.4 $ 14,451 Vested and expected to vest at December 31, 2015 5,786,950 $ 2.08 7.5 $ 19,990 The weighted-average grant date fair value of options granted to employees was $3.13, $0.42 and $0.35 per share for the year ended December 2015, 2014 and 2013. The grant date fair value of options vested was $782 thousand, $339 thousand and $72 thousand, respectively, during the year ended December 31, 2015, 2014 and 2013. Aggregate intrinsic value represents the difference between the estimated fair value of the underlying common stock and the exercise price of outstanding, in-the-money options. The aggregate intrinsic value of option exercised was insignificant for the year ended December 31, 2015, 2014 and 2013. At December 31, 2015, total unrecognized compensation cost related to stock-based awards granted to employees, net of estimated forfeitures, was $5.2 million which is expected to be recognized over a weighted-average period of 3.2 years. Determination of Fair Value The determination of the fair value of stock options on the date of grant using an option-pricing model is affected by the estimated fair value of the Company’s common stock, as well as assumptions regarding a number of complex and subjective variables. The variables used to calculate the fair value of stock options using the Black-Scholes option-pricing model include actual and projected employee stock option exercise behaviors, expected price volatility of the Company’s common stock, the risk-free interest rate and expected dividends. Each of these inputs is subjective and generally requires significant judgment to determine. Fair Value of Common Stock Prior to the Merger, the fair value of the common stock underlying the stock-based awards was determined by ViewRay Technologies, Inc.’s board of directors, with input from management and third-party valuations. Post-Merger, the Company’s common stock shares are listed on the OTC Bulletin Board. Fair value of the common stock is the adjusted closing price of its common stock on the trading date. Expected Term The expected term represents the period that the Company’s option awards are expected to be outstanding. The Company considers several factors in estimating the expected term of options granted, including the expected lives used by a peer group of companies within the Company’s industry that the Company considers to be comparable to its business and the historical option exercise behavior of its employees, which the Company believes is representative of future behavior. Expected Volatility As the Company does not have a sufficient trading history for its common stock, the expected stock price volatility for the Company’s common stock was estimated by taking the average historic price volatility for industry peers based on daily price observations over a period equivalent to the expected term of the stock option grants. Industry peers consist of several public companies in the Company’s industry which were the same as the comparable companies used in the common stock valuation analysis. The Company intends to continue to consistently apply this process using the same or similar public companies until a sufficient amount of historical information regarding the volatility of its own share price becomes available, or unless circumstances change such that the identified companies are no longer similar to the Company, in which case, more suitable companies whose share prices are publicly available would be used in the calculation. Risk-Free Interest Rate The risk-free interest rate is based on the zero coupon U.S. Treasury notes, with maturities similar to the expected term of the options. Expected Dividend Yield The Company does not anticipate paying any dividends in the foreseeable future and, therefore, uses an expected dividend yield of zero in the Black-Scholes option-valuation model. In addition to the Black-Scholes assumptions discussed immediately above, the estimated forfeiture rate also has a significant impact on the related stock-based compensation. The forfeiture rate of stock options is estimated at the time of grant and revised in subsequent periods if actual forfeitures differ from those estimates. The Company uses historical data to estimate pre-vesting option forfeitures and records stock-based compensation expense only for those awards that are expected to vest. The fair value of employee stock options was estimated at the date of grant using a Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, 2015 2014 2013 Expected term (in years) 5.9 5.7 6.2 Expected volatility (%) 68.7% 50.7% 52.4% Risk-free interest rate (%) 1.8% 1.8% 1.2% Expected dividend yield (%) 0.0% 0.0% 0.0% Stock-Based Compensation Expense Total stock-based compensation expense recognized in the Company’s consolidated statements of operations is classified as follows (in thousands): Year Ended December 31, 2015 2014 2013 Research and development $ 262 $ 85 $ 29 Selling and marketing 50 15 9 General and administrative 754 218 181 Total stock-based compensation expense $ 1,066 $ 318 $ 219 During the years ended December 31, 2015, 2014 and 2013 there were no stock-based compensation expenses capitalized as a component of inventory or recognized in cost of revenue. Stock-based compensation relating to stock-based awards granted to consultants was insignificant for the years ended December 31, 2015, 2014 and 2013.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	15 . Income Taxes The following reconciles the differences between income taxes computed at the federal income tax rate and the provision for income taxes: Year Ended December 31, 2015 2014 2013 Expected income tax benefit at the federal statutory rate 34.0 % 34.0 % 34.0 % State taxes, net of federal benefit (0.8 ) 3.7 1.5 Change in effective tax rate (0.9 ) 1.3 0.0 Non-deductible items and other (0.5 ) 0.4 (2.1 ) Federal and state credits (0.7 ) 1.2 2.0 Change in valuation allowance (31.10 ) (40.60 ) (35.40 ) Total 0.0 % 0.0 % 0.0 % Deferred income taxes reflect the net effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The principal components of the Company’s net deferred tax assets consisted of the following at December 31, 2015 and 2014 (in thousands): Year Ended December 31, 2015 2014 Net operating loss carryforwards $ 60,979 $ 46,024 Research and development tax credits 1,731 2,441 Reserves and accruals 966 724 Other 2,433 2,948 Total deferred tax assets 66,109 52,137 Valuation allowance (66,109 ) (52,137 ) Net deferred tax assets $ — $ — The Company maintains a valuation allowance related to its deferred tax asset position when management believes it is more likely than not that the net deferred tax assets will not be realized in the future. The Company’s valuation allowance increased by $14.0 million and $13.7 million during the year ended December 31, 2015 and 2014. At December 31, 2015, the Company had federal net operating loss carryforwards of $170.1 million, which begin to expire in the year ended December 31, 2024, and $111.8 million related to state net operating loss carryforwards, which begin to expire in the year ending December 31, 2019. The Company had federal research and development tax credit carryforwards of $2.5 million at the year ended December 31, 2015. These credits expire at various dates through the year ending December 31, 2024. Under the provisions of the Internal Revenue Code, or IRC, net operating loss and credit carryforwards and other tax attributes may be subject to limitation if there has been a significant change in ownership of the Company, as defined by the IRC. The Company believes it has experienced at least one ownership change in the past. The Company is currently analyzing the tax impact of such ownership change on its federal net operating loss and credit carryforwards. Future owner or equity shifts, including an IPO, could result in limitations on net operating loss and credit carryforwards. Because of the net operating loss and credit carryforwards, all of the Company’s federal tax returns and state returns since the year ended December 31, 2004 remain subject to federal and California examination. The Company accounts for uncertain tax positions using a “more-likely-than-not” threshold. The evaluation of uncertain tax positions is based on factors including, but not limited to, changes in tax law, the measurement of tax positions taken or expected to be taken in tax returns, the effective settlement of matters subject to audit, new audit activity and changes in facts or circumstances related to a tax position. The Company evaluates these tax positions on an annual basis. In addition, the Company also accrues for potential interest and penalties related to unrecognized tax benefits in income tax expense. At December 31, 2015 and 2014, the Company’s unrecognized tax benefits consist of the following: Year Ended December 31, 2015 2014 Unrecognized tax benefit, beginning of period $ — $ — Gross increases — current year tax positions 130 — Gross decreases — current year tax positions — — Gross increases — prior year tax positions 612 — Unrecognized tax benefit, end of period $ 742 $ —

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2015
Postemployment Benefits [Abstract]
Employee Benefits	16 . Employee Benefits The Company has a 401(k) Plan which covers its eligible employees. The 401(k) Plan permits the participants to defer a portion of their compensation in accordance with the provisions of Section 401(k) of the IRC. At its discretion, the Company can match a portion of the participants’ contributions or make profit-sharing contributions. There was no matching or profit-sharing contributions during the years ended December 31, 2015, 2014 or 2013.

Net Loss per Share

Net Loss per Share	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Net Loss per Share	17 . Net Loss per Share The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented (in thousands, except share and per share data): Year Ended December 31, 2015 2014 2014 Net loss $ (44,995 ) $ (33,800 ) $ (27,222 ) Cumulative dividends on convertible preferred stock — — (2,898 ) Deemed capital contribution on conversion of Series C convertible preferred stock into common stock — — 8,783 Deemed dividend on convertible preferred stock extinguishment — — (6,863 ) Deemed capital contribution on repurchase of Series A preferred stock — 9 — Net loss attributable to common stockholders $ (44,995 ) $ (33,791 ) $ (28,200 ) Weighted-average common shares used in computing net loss per share, basic and diluted 17,432,434 892,315 815,340 Net loss per share, basic and diluted $ (2.58 ) $ (37.87 ) $ (34.59 ) The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share for the periods presented because including them would have had an anti-dilutive effect: Year Ended December 31, 2015 2014 2013 Convertible preferred stock (if converted) 16,558,330 25,078,396 20,901,591 Options to purchase common stock 5,032,768 3,766,704 2,799,118 Convertible preferred stock warrant 71,318 128,231 5,619 Common stock warrant 142,513 — —

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment and Geographic Information	18 . Segment and Geographic Information The Company has one business activity, which is radiation therapy technology combined with magnetic resonance imaging, and operates in one reportable segment. The Company’s chief operating decision-maker, its chief executive officer, reviews its operating results on an aggregate basis for purposes of allocating resources and evaluating financial performance. Also, the Company does not have segment managers as the Company manages its operations as a single operating segment. The following table sets forth revenue by geographic area on the customers’ location (in thousands): Year ended December 31, 2015 2014 2013 United States $ 5,332 $ 6,399 $ 3,159 Korea 4,988 — — Rest of world 70 — — Total revenue $ 10,390 $ 6,399 $ 3,159 At December 31, 2015 and 2014, all long-lived assets are located in the United States.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Related Party Transactions	19 . Related Party Transactions As discussed in Note 8, the Company pays a royalty to UFRF, a common stockholder, related to a licensing agreement.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2015
Subsequent Events [Abstract]
Subsequent Events	20 . Subsequent Events The Company has evaluated subsequent events through March 28, 2016, the date on which these consolidated financial statements were issued. No significant subsequent events to this date would have had material impact on the Company’s consolidated financial statements as of and for the year ended December 31, 2015.

Summary of Significant Accoun28

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation The consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America, or GAAP, and pursuant to the rules and regulation of the Securities and Exchanges Commission, or SEC. The consolidated financial statements include the accounts of ViewRay, Inc. and its wholly-owned subsidiary, ViewRay Technologies, Inc. All significant inter-company accounts and transactions have been eliminated in consolidation. Certain amounts in the consolidated balance sheet at December 31, 2014 were reclassified to conform to the current year presentation. These reclassifications did not affect the previously reported total assets, total liabilities, consolidated statements of operations or stockholders’ deficit.
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported and disclosed in the consolidated financial statements and accompanying notes. Such estimates include, but are not limited to, allocation of revenue to its multiple deliverable elements, inventory write-downs to reflect net realizable value, assumptions used in the valuation of stock-based awards and a convertible preferred stock warrant, accrued losses from purchase commitments and valuation allowances against deferred tax assets. Actual results could differ from those estimates.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. The Company deposits its cash primarily in checking and money market accounts.
Restricted Cash	Restricted Cash At December 31, 2015, and 2014, the Company had an aggregate of $0.9 million and $1.1 million of outstanding letters of credit related to its operating leases and its contractual obligations with distributors and customers. The letters of credit are collateralized by a restricted cash deposit account, which is presented as part of noncurrent assets on the balance sheets because the Company is not certain when the restriction will be lifted on the collateralized letters of credit. At December 31, 2015, and 2014, no amounts were drawn on the letters of credit.
Concentration of Credit Risk, Other Risks and Uncertainties	Concentration of Credit Risk, Other Risks and Uncertainties Financial instruments that potentially subject the Company to concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable. Cash and cash equivalents are deposited in checking and money market accounts with various financial institutions. At times, cash balances may be in excess of the amounts insured by the Federal Deposit Insurance Corporation. Management believes the financial risk associated with these balances is minimal and has not experienced any losses to date. The Company performs periodic credit evaluations of its customers’ financial condition and generally requires deposits from its customers. The Company’s accounts receivable was derived from billings to customers. The Company’s customers representing greater than 10% of accounts receivable and revenue for the periods presented were as follows: Revenue Accounts Receivables Year Ended December 31, December 31, Customers 2015 2014 2013 2015 2014 Customer A * * 72% * * Customer B * 52% * * * Customer C * 40% * * * Customer D 48% * * * 100% Customer E 43% * * 94% * State of Ohio * * 28% * * The Company’s future results of operations involve a number of risks and uncertainties. Factors that could affect the Company’s future operating results and cause actual results to vary materially from expectations include, but are not limited to, rapid technological change, continued acceptance of MRIdian, competition from substitute products and larger companies, protection of proprietary technology, ability to maintain distributor relationships and dependence on key individuals. Furthermore, new products to be developed by the Company require approval from the FDA or other international regulatory agencies prior to commercial sales. There can be no assurance that the Company’s future products will receive the necessary clearances. The Company relies on a concentrated number of suppliers to manufacture essentially all of the components used in MRIdian. The Company’s suppliers may encounter problems during manufacturing due to a variety of reasons, including failure to comply with applicable regulations, including the FDA’s Quality System Regulation, equipment malfunction and environmental factors, any of which could delay or impede their ability to meet demand.
Accounts Receivables and Allowance for Doubtful Accounts	Accounts Receivables and Allowance for Doubtful Accounts Accounts receivable are recorded at the invoiced amount, net of any allowance for doubtful accounts, and do not bear interest. The allowance for doubtful accounts, if any, is based on the assessment of the collectability of customer accounts. Based on the specific customer and the current economic conditions, there was no allowance for doubtful accounts recorded at December 31, 2015 and 2014.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Financial instruments consist of cash and cash equivalents, accounts receivable, restricted cash, prepaid expenses and other current assets, accounts payable, accrued liabilities, notes payable, convertible preferred stock warrant liability and long-term debt. Cash equivalents are stated at amortized cost, which approximates fair value at the balance sheet dates, due to the short period of time to maturity. Accounts receivable, prepaid expenses and other current assets, accounts payable, accrued liabilities and notes payable are stated at their carrying value, which approximates fair value due to the short time to the expected receipt or payment date. The convertible preferred stock warrant liability is carried at fair value. The carrying amount of the Company’s long-term debt approximates fair value as the stated interest rate approximates market rates currently available to the Company.
Inventory and Deposits on Purchased Inventory	Inventory and Deposits on Purchased Inventory Inventory consists of purchased components for assembling MRIdian systems and other direct and indirect costs associated with MRIdian system installation. Inventory is stated at the lower of cost or market value. All inventories expected to be placed in service during normal operating cycle of ViewRay Technologies, Inc. for the delivery and assembly of MRIdian systems, including items expected to be on hand for more than one year, are classified as current assets. Effective January 1, 2015, ViewRay Technologies, Inc. made a voluntary change to its accounting policy for inventory cost basis. Under the previous accounting policy, inventory items were recorded on a first-in, first-out basis through specific identification. Purchased components were assigned to each MRIdian system at original cost. Under the new accounting policy, ViewRay Technologies, Inc. recorded inventory at weighted average cost basis. The Company believes that this change is preferable because it will be more efficient for the Company to keep track of its inventory cost. The first-in, first-out cost basis through specific identification accounting policy was manageable at the time when ViewRay Technologies, Inc. had limited MRIdian system installations (one MRIdian system installation during the year ended December 31, 2013, and another two MRIdian system installation during the year ended December 31, 2014). However, due to the Company’s growing business and sales, the number of planned MRIdian system installation has been increasing. Purchased components are no longer assigned to specific MRIdian system installation. Along with the Company’s increased components purchasing activities, the new accounting policy will significantly reduce the Company’s burden and cost of inventory management. In accordance with applicable accounting literature, a change in inventory cost basis is treated as a change in accounting principle and requires retrospective application. The accounting policy change has no cumulative effect on ViewRay Technologies, Inc. annual statements of operations prior to January 1, 2015. Therefore, no retrospective adjustment for the Company’s annual consolidated financial statements are required. The Company reduces the carrying value of its inventory for the difference between cost and net realizable value and records a charge to cost of product revenues for the amount required to reduce the carrying value of inventory to net realizable value. The Company recorded an inventory lower of cost and market adjustment of $2.6 million, $598 thousand and $4.6 million during the years ended December 31, 2015, 2014 and 2013, respectively. The Company records inventory items which have been paid for but not yet received and titles have not yet transferred to the Company as deposits on purchased inventory. Deposits on purchased inventory are included within current assets as the related inventory items are expected to be received and used in MRIdian systems within the Company’s normal operating cycle. The Company assesses the recoverability of deposits on purchased inventory based on credit assessments of the vendors and their history supplying these assets. At December 31, 2015, the Company did not have any instances whereby deposits for purchased inventory were written off or the purchased inventory was not delivered.
Shipping and Handling Costs	Shipping and Handling Costs Shipping and handling costs for product shipments to customers are included in cost of product revenue. Shipping and handling costs incurred for inventory purchases are capitalized in inventory and expensed in cost of product revenue. These costs are not passed on to customers.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost. Depreciation is computed over estimated useful lives, ranging from two to 15 years of the related assets using the straight-line method. Acquired software is recorded at cost. Amortization of acquired software generally occurs over three years using the straight-line method. Leasehold improvements are amortized on a straight-line basis over the shorter of the useful life or term of the lease. Upon retirement or sale, the cost and related accumulated depreciation are removed from the balance sheet and the resulting gain or loss is recorded to general and administrative expense in the accompanying statements of operations. Routine expenditures for maintenance and repairs are expensed as incurred. Depreciation and amortization periods for property and equipment are as follows: Property and Equipment Estimated Useful Life Prototype 2 years Machinery and equipment 5 – 15 years Furniture and fixture 5 – 10 years Software 3 years Leasehold improvements Lesser of estimated useful life or remaining lease term
Asset Retirement Obligation	Asset Retirement Obligation In connection with certain lease agreements entered into in October 2015, the Company has a legal requirement to remove long-lived assets constructed on leased property and to restore the leased property to its original condition. The Company records the fair value of the liability for a legal obligation to retire an asset in the period in which the obligation is incurred if a reasonable estimate of fair value can be made. The Company measures the fair value of the asset retirement obligation based upon the present value of the expected future payments, and recognized asset retirement obligation of $250,000 at inception. The liability is accreted to its present value each period and the capitalized cost is depreciated over the remaining lease term. Accretion expense is calculated by applying the effective interest rate to the carrying amount of the liability at the beginning of each period. The effective interest rate is the credit-adjusted risk-free rate applied when the liability was initially measured and recognized. At December 31, 2015, the Company had outstanding asset retirement obligations of $258,000, which was included in other long-term liabilities in the accompanying consolidated balance sheets. For the year ended December 31, 2015, the Company recognized accretion expenses of $8,000 in the accompanying statement of operations.
Intangible Assets	Intangible Assets Intangible assets consist primarily of patents and license acquisition costs associated with certain technology components incorporated into the Company’s MRIdian systems. The Company capitalizes the cost and amortizes it on a straight-line basis over the estimated useful lives, which is generally three years for license cost and five to seven years for patents.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets The Company reviews the recoverability of long-lived assets, including equipment, leasehold improvements, software and intangible assets when events or changes in circumstances occur that indicate that the carrying value of the asset may not be recoverable. The assessment of possible impairment is based on the ability to recover the carrying value of the assets from the expected future cash flows (undiscounted and without interest charge) of the related operations. If these cash flows are less than the carrying value of such assets, an impairment loss for the difference between the estimated fair value and carrying value is recorded. There was no impairment loss recognized during the years ended December 31, 2015, 2014 and 2013.
Deferred Offering Costs	Deferred Offering Costs ViewRay Technologies, Inc. capitalizes qualified legal, accounting and other direct costs related to its efforts to raise capital through a public sale of its common stock in its planned IPO. These costs are recorded in deferred offering costs in the accompanying balance sheets and will be
Comprehensive Loss	Comprehensive Loss Comprehensive loss is the change in equity of a company during a period from transactions and other events and circumstances, excluding transactions resulting from investment owners and distribution to owners. For the periods presented, comprehensive loss did not differ from net loss.
Revenue Recognition	Revenue Recognition The Company derives revenue primarily from the sale of the systems and related services, which are predominantly sales of MRIdian, as well as support and maintenance services on purchased systems. In all sales arrangements, the Company recognizes revenues when there is persuasive evidence of an arrangement, the fee is fixed or determinable, collection of the fee is reasonably assured and delivery has occurred. For sales of MRIdian systems, the Company currently recognizes product revenue upon receipt of customer acceptance. For sales of the related support and maintenance services, the Company recognizes service revenue on a straight-line basis over the service contract term, which is typically 12 months.
Multiple Elements	Multiple Elements Based on the nature of the Company’s business, it frequently enters into sales arrangements with customers that contain multiple elements or deliverables. In situations where a deliverable in a multi-element arrangement has value to the customer on a stand-alone basis, the Company is required to allocate the fair value of the various elements based on the selling price of each element. The principal deliverables consist of (i) sale of MRIdian systems, which generally includes installation, site preparation and software, and (ii) product support, which includes extended service and maintenance. The Company determines selling prices using vendor specific objective evidence, or VSOE, if it exists, or third party evidence, or TPE. If neither VSOE nor TPE exists for a deliverable, the Company uses best estimated selling price, or BESP. The Company allocates revenue to its multiple elements generally using the relative fair values as determined by BESP. The Company regularly reviews VSOE, TPE and BESP for all of its MRIdian systems and services.
Product Revenue	Product Revenue Product revenue is derived primarily from the sales of MRIdian. The system contains both software and non-software components that together deliver essential functionality. However, because MRIdian includes hardware products as well as software components that function together with the hardware components to deliver MRIdian’s essential functionality, the revenue from the sale of MRIdian systems does not fall within the scope of the software revenue recognition rules. The related customer contracts currently call for on-site assembly of the system components and system integration. Once the system installation is completed, the Company performs a detailed demonstration with the customer showing that MRIdian meets the standard product specifications. After successful demonstration, the customer signs a document indicating customer acceptance. All contracts include customer deposits upon signing of the agreement with final payment generally due upon customer acceptance. Revenue recognition for MRIdian systems generally occurs when the customer acknowledges that the system operates in accordance with standard product specifications, the customer accepts the installed unit and title and risk of loss are transferred to the customer.
Service Revenue	Service Revenue Service revenue is derived primarily from maintenance services. Service revenue is deferred and recognized ratably over the service period.
Grant Revenue	Grant Revenue The Company receives payments for the achievement of certain milestones under government grants over a contractually defined period. These payments are nonrefundable. Government grants generally provide the Company with fixed payments and a contractually defined period. Grant revenues are recognized as milestones under the grant program are achieved and is earned through reimbursements for the qualifying expenses incurred by the Company. The Company retains ownership and exclusive rights to all inventions made under these arrangements. Upon the completion of the Company’s government grants, no further obligations exist under these arrangements. The Company retains the rights to commercialize the technology it developed under government grants without any royalty obligations. The Company entered into a loan agreement with the county redevelopment fund in the State of Ohio to fund the renovation of its Ohio headquarters. Under the terms of the loan agreement, the lender may forgive a portion of the loan if the Company meets certain permanent job creation requirement within the State of Ohio. Grant revenues are recognized when the Company meets the employment requirement and receives the loan forgiveness notice from the lender.
Customer Deposits	Customer Deposits Customer deposits represent payments received in advance of system installation. For domestic sales, advance payments received prior to customer acceptance are recorded as customer deposits. For international sales, advance payments are initially recorded as customer deposits and are subsequently reclassified to deferred revenue upon inventory shipment when the title and risk of loss of inventory items transferred to customers. All customer deposits, including those that are expected to be a deposit for more than one year, are classified as current liabilities based on consideration of the Company’s normal operating cycle (the time between acquisition of the inventory components and the final cash collection from customers on these inventory components) which is in excess of one year.
Deferred Revenue and Deferred Cost of Revenue	Deferred Revenue and Deferred Cost of Revenue Deferred revenue consists of deferred product revenue and deferred service revenue. Deferred product revenue arises from timing differences between the fulfillment of other contract deliverables and satisfaction of all revenue recognition criteria consistent with the Company’s revenue recognition policy. Deferred service revenue results from the advance billing for services to be delivered over a period of time. Deferred revenues expected to be realized within one year are classified as current liabilities. Deferred cost of revenue consists of cost for inventory items that have been shipped with title and risk of loss transferred to customer but the customer acceptance has not been received. Deferred cost of revenue is included as part of current assets as the corresponding deferred product revenue are expected to be realized within one year. The inventories recorded in deferred cost of revenue are also included in the inventory lower of cost or market analysis. At December 31, 2015 and 2014, no reserve was required for deferred cost of revenue.
Research and Development Costs	Research and Development Costs Expenditures, including payroll, contractor expenses and supplies, for research and development of products and manufacturing processes are expensed as incurred. Software development costs incurred subsequent to establishing technological feasibility are capitalized through the general release of MRIdian systems that contain the embedded software elements. Technological feasibility is demonstrated by the completion of a working model. The Company has not capitalized any software development costs at December 31, 2015 or 2014, since the costs incurred subsequent to achieving technological feasibility and completing the research and development for the software components were immaterial.
Stock-Based Compensation	Stock-Based Compensation The Company uses the Black-Scholes option-pricing model as the method for estimating the fair value of stock options. The Black-Scholes option-pricing model requires the use of highly subjective and complex assumptions that determine the fair value of share-based awards, including the options’ expected term and the price volatility of the underlying stock. The fair value of the portion of the award that is ultimately expected to vest is recognized as compensation expense over the awards’ requisite service periods in the statements of operations. The Company attributes the value of share-based compensation to expense using the straight-line method.
Medical Device Excise Tax	Medical Device Excise Tax Medical Device Excise Tax, or MDET, Section 4191 of the Internal Revenue Code enacted by the Health Care and Education Reconciliation Act of 2010, in conjunction with the Patient Protection and Affordable Care Act, established a 2.3% excise tax on medical devices sold domestically beginning on January 1, 2013. The Company included the cost of MDET in cost of product revenue during the years ended December 31, 2015, 2014 and 2013, net of amounts directly billed to the customer for this tax, if any.
Deferred Commissions	Deferred Commissions Deferred commissions are the direct and incremental costs directly associated with the MRIdian system contracts with customers, which primarily consist of sales commissions to our direct sales force. The commissions are deferred and expensed in proportion to the revenue recognized upon the acceptance of the MRIdian system. At December 31, 2015 and 2014, the Company had $799 thousand and $221 thousand deferred commissions recorded as part of prepaid expenses and other current assets on the accompanying consolidated balance sheets.
Income Taxes	Income Taxes The Company uses the asset and liability method of accounting for income taxes. Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Deferred tax expense or benefit is the result of changes in the deferred tax assets and liabilities. Valuation allowances are established when necessary to reduce deferred tax assets where, based upon the available evidence, management concludes that it is more-likely-than not that the deferred tax assets will not be realized. Because of the uncertainty of the realization of the deferred tax assets, the Company has recorded a full valuation allowance against its net deferred tax assets. In evaluating the ability to recover its deferred income tax assets, the Company considers all available positive and negative evidence, including its operating results, ongoing tax planning and forecasts of future taxable income on a jurisdiction-by-jurisdiction basis. In the event the Company was to determine that it would be able to realize its deferred income tax assets in the future in excess of their net recorded amount, it would make an adjustment to the valuation allowance which would reduce the provision for income taxes. Reserves are provided for tax benefits for which realization is uncertain. Such benefits are only recognized when the underlying tax position is considered more likely than not to be sustained on examination by a taxing authority, assuming they possess full knowledge of the position and facts. It is the Company’s policy to include any penalties and interest related to income taxes in its income tax provision; however, the Company currently has no penalties or interest related to income taxes. The earliest year that the Company is subject to examination is the year ended December 31, 2004.
Convertible Preferred Stock Warrant Liability	Convertible Preferred Stock Warrant Liability The Company’s warrant to purchase convertible preferred stock is classified as a liability on the consolidated balance sheets at fair value upon issuance because the warrant is exercisable for contingently redeemable preferred stock which is classified outside of stockholders’ deficit. The warrant is subject to re-measurement to fair value at each balance sheet date, and any change in fair value is recognized in the consolidated statements of operations as other income (expense), net. In July 2015, upon the Merger of the Company and ViewRay Technologies, Inc., and the Private Placement, the convertible preferred stock warrants were converted into warrants to purchase the Company’s common stock, and the fair value of the preferred stock warrant liability was reclassified to additional paid-in capital.
Net Loss per Share	Net Loss per Share The Company’s basic net loss per share attributable to common stockholders is calculated by dividing the net loss attributable to common stockholders by the weighted-average number of shares of common stock outstanding for the period. The net loss attributable to common stockholders was not allocated to the convertible preferred stock under the two-class method as the convertible preferred stock do not have a contractual obligation to share in the net loss attributable to common stockholders. The diluted net loss per share attributable to common stockholders is computed by giving effect to all potential common stock equivalents outstanding for the period determined using the treasury stock method. For purposes of this calculation, convertible preferred stock, stock options, and warrants to purchase convertible preferred stock and common stock are considered to be common stock equivalents but have been excluded from the calculation of diluted net loss per share attributable to common stockholders as their effect is anti-dilutive.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In November 2015, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2015-17, Balance Sheet Classification of Deferred Taxes, In July 2015, the FASB issued ASU 2015-11, Simplifying the Measurement of Inventory In April 2015, the FASB issued ASU 2015-03, Simplifying the Presentation of Debt Issuance Costs In August 2014, the FASB issued ASU 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40), In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606) In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842)

Summary of Significant Accoun29

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Accounting Policies [Abstract]
Schedule of Customers Representing Greater than 10% of Accounts Receivable and Revenue	The Company’s customers representing greater than 10% of accounts receivable and revenue for the periods presented were as follows: Revenue Accounts Receivables Year Ended December 31, December 31, Customers 2015 2014 2013 2015 2014 Customer A * * 72% * * Customer B * 52% * * * Customer C * 40% * * * Customer D 48% * * * 100% Customer E 43% * * 94% * State of Ohio * * 28% * *
Schedule of Depreciation and Amortization Periods for Property and Equipment	Depreciation and amortization periods for property and equipment are as follows: Property and Equipment Estimated Useful Life Prototype 2 years Machinery and equipment 5 – 15 years Furniture and fixture 5 – 10 years Software 3 years Leasehold improvements Lesser of estimated useful life or remaining lease term

Balance Sheet Components (Table

Balance Sheet Components (Tables)	12 Months Ended
	Dec. 31, 2015
Balance Sheet Related Disclosures [Abstract]
Schedule of Property and Equipment	Property and equipment consisted of the following (in thousands): December 31 2015 2014 Prototype $ 6,492 $ 6,342 Machine and equipment 7,128 4,214 Leasehold improvements 1,532 1,270 Furniture and fixtures 350 263 Software 832 647 Construction in progress 1,851 — Property and equipment, gross 18,185 12,736 Less: accumulated depreciation and amortization (10,879 ) (9,805 ) Property and equipment, net $ 7,306 $ 2,931
Summary of Intangible Assets	Intangible assets consisted of the following (in thousands): December 31 2015 2014 License cost $ 500 $ 500 Patents 104 — Intangible assets, gross $ 604 $ 500 Accumulated amortization (404 ) (236 ) Intangible assets, net $ 200 $ 264
Summary of Estimated Future Amortization Expense	At December 31, 2015, the estimated future amortization expense of purchased intangible assets was as follows (in thousands): Year Ended December 31, Estimated Amortization Expense 2016 $ 115 2017 18 2018 18 2019 18 2020 18 Thereafter 13 Total amortization expense $ 200
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following (in thousands): December 31 2015 2014 Accrued payroll and related benefits $ 1,938 $ 1,652 Accrued accounts payable 1,880 143 Sales tax and medical device excise tax payable 219 499 Accrued legal and accounting 857 901 Accrued interest — 142 Other 519 296 Total accrued liabilities $ 5,413 $ 3,633
Schedule of Deferred Revenue	Deferred revenue consisted of the following (in thousands): December 31 2015 2014 Deferred revenue: Product $ 5,050 $ 6,919 Services 911 442 Total deferred revenue 5,961 7,361 Less: current portion of deferred revenue (5,616 ) (7,361 ) Noncurrent portion of deferred revenue $ 345 $ —

Fair Value of Financial Instr31

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Schedule of Fair Value of Financial Liabilities	The following table sets forth the fair value of the Company’s financial liabilities by level within the fair value hierarchy (in thousands): At December 31, 2014 Level 1 Level 2 Level 3 Total Convertible preferred stock warrant liability $ — $ — $ 138 $ 138
Summary of Changes in Fair Value of Level 3 Financial Liabilities	The following table sets forth a summary of the changes in the fair value of the Company’s Level 3 financial liabilities (in thousands): Year Ended December 31, 2015 2014 2013 Fair value, beginning of period $ 138 $ 158 $ — Issuance of convertible preferred stock warrant — — 158 Change in fair value of Level 3 financial liabilities (45 ) (20 ) — Fair value, end of period $ 93 $ 138 $ 158

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Scheduled Future Payments on Term Loan	The Company’s scheduled future payment on the CRG Term Loan at December 31, 2015 are as follows (in thousands): Year Ended December 31, 2016 $ 2,541 2017 2,652 2018 12,019 2019 19,644 2020 and thereafter 10,506 Total future payments $ 47,362 Less: amount representing interest and end-of-term facility fee (17,362 ) Total principal amount 30,000 Less: unamortized debt discount (984 ) Carrying value of long-term debt $ 29,016 Less: current portion — Long-term portion $ 29,016

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments Under Non-cancelable Operating Lease Agreements	At December 31, 2015, the future minimum payments for the operating leases are as follows (in thousands): Year Ended December 31, 2016 $ 1,113 2017 1,106 2018 963 2019 823 Total future minimum payments $ 4,005

Common Stock Reserved for Iss34

Common Stock Reserved for Issuance (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Schedule of Common Stock Reserved for Future Issuance	The common stock reserved for future issuance at December 31, 2015 and 2014 was as follows: December 31 2015 2014 Conversion of outstanding convertible preferred stock — 27,654,928 Shares underlying outstanding stock options 6,053,672 4,248,504 Shares available for future stock option grants 3,166,968 295,101 ESPP shares available for issuance 285,621 — Warrant to purchase convertible preferred stock — 128,231 Warrant to purchase common stock 326,991 — Total shares of common stock reserved 9,833,252 32,326,764

Convertible Preferred Stock (Ta

Convertible Preferred Stock (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Schedule of Shares of Convertible Preferred Stock and Common Stock	The changes in the shares of convertible preferred stock and common stock during the years ended December 31, 2015, 2014 and 2013 were as follows: Series A Convertible Preferred Stock Extinguished Series B-1 Convertible Preferred Stock Extinguished Series C Convertible Preferred Stock Extinguished Series D-1 Convertible Preferred Stock Extinguished Series D-2 Convertible Preferred Stock New Series B Convertible Preferred Stock New Series C Convertible Preferred Stock Total Convertible Preferred Stock Common Stock Balance at December 31, 2012 163,462 6,321,238 9,108,533 1,155,172 — — — 16,748,405 730,203 Issuance of Series D-1 convertible preferred stock — — — 983,558 — — — 983,558 — Issuance of Series D-2 convertible preferred stock — — — — 3,013,797 — — 3,013,797 — Conversion of Series C convertible preferred stock and related dividends dividends into common stock and deemed capital contribution — — (1,470,485 ) — — — — (1,470,485 ) 147,051 Conversion of accrued dividends into Series D-2 convertible preferred stock — — — — 3,196,417 — — 3,196,417 — Extinguishment of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock — (6,321,238 ) (7,638,048 ) (2,138,730 ) (6,210,214 ) — — (22,308,230 ) — Exchange of new Series B convertible preferred stock and deemed dividend — — — — — 22,308,230 — 22,308,230 — Issuance of new Series C convertible preferred stock — — — — — — 2,564,638 2,564,638 — Issuance of common stock from option exercise — — — — — — — — 1,463 Balance at December 31, 2013 163,462 — — — — 22,308,230 2,564,638 25,036,330 878,717 Repurchase of Series A convertible preferred stock and deemed capital contribution (1,353 ) — — — — — — (1,353 ) — Issuance of Series C convertible preferred stock — — — — — — 880,546 880,546 — Conversion of convertible promissory notes into Series C convertible preferred stock — — — — — — 1,739,405 1,739,405 — Issuance of common stock from option exercise — — — — — — — — 28,320 Balance at December 31, 2014 162,109 — — — — 22,308,230 5,184,589 27,654,928 907,037 Issuance of Series C convertible preferred stock — — — — — — 2,727,059 2,727,059 — Conversion of convertible preferred stock into common stock in connection with the merger (162,109 ) — — — — (22,308,230 ) (7,911,648 ) (30,381,987 ) 30,381,987 Issuance of common stock upon private placement — — — — — — — — 5,884,504 Issuance of common stock to Mirax — — — — — — — — 1,000,005 Issuance of common stock from option exercise — — — — — — — — 31,427 Balance at December 31, 2015 — — — — — — — — 38,204,960
Components of Convertible Preferred Stock	Convertible preferred stock as of December 31, 2015 and 2014 consisted of the following (in thousands, except share data): December 31, 2015 Shares Authorized Shares Issued and Outstanding Aggregate Liquidation Preference Net Carrying Value Series A 398,500 — $ — $ — Series B 60,500,000 — — — Series C 19,812,497 — — — Total 80,710,997 $ — $ — $ — December 31, 2014 Shares Authorized Shares Issued and Outstanding Aggregate Liquidation Preference Net Carrying Value Series A 398,500 162,109 $ 3,004 $ 3,003 Series B 60,500,000 22,308,230 113,405 112,080 Series C 13,562,497 5,184,589 30,323 30,027 Total 74,460,997 27,654,928 $ 146,732 $ 145,110

Warrants (Tables)

Warrants (Tables)	12 Months Ended
	Dec. 31, 2015
Equity [Abstract]
Summary of Assumptions to Use Option Pricing Model	The Company used the Black-Scholes option-pricing model to estimate the fair value of the convertible preferred stock warrant with the following assumptions: Upon the Closing of the Merger on July 23, 2015 December 31, 2014 Common Stock Warrants: Expected term (in years) 5.0 5.3 Expected volatility (%) 31.8% 30.0% Risk-free interest rate (%) 1.7% 1.7% Expected dividend yield (%) 0% 0% The fair value of the placement warrants was valued at their grant dates using the Black-Scholes pricing model and the following weighted average assumptions: Upon Issuance Common Stock Warrants: Expected term (in years) 5.0 Expected volatility (%) 31.8% Risk-free interest rate (%) 1.6% Expected dividend yield (%) 0%

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Company's Stock Option Activity and Related Information	A summary of the Company’s stock option activity and related information is as follows: Options Outstanding Shares Available for Grant Number of Stock Options Outstanding Weighted- Average Exercise Price Weighted- Average Remaining Contractual (Years) Aggregate Intrinsic Value (In thousands) Balance at January 1, 2013 306,097 1,907,644 $ 0.71 6.3 $ 28 Additional authorized 2,359,662 Granted (1,190,349 ) 1,190,349 0.70 Exercised (1,463 ) 0.68 Cancelled 372,957 (372,957 ) 0.69 Balance at December 31, 2013 1,848,367 2,723,573 0.71 7.7 $ 138 Granted (1,642,799 ) 1,642,799 0.84 Exercised — (28,320 ) 0.73 Cancelled 89,533 (89,533 ) 0.74 Balance at December 31, 2014 295,101 4,248,519 0.76 7.7 $ 8,343 Additional authorized 4,708,447 — Granted (1,975,673 ) 1,975,673 5.03 Exercised — (31,427 ) 0.76 Cancelled 139,093 (139,093 ) 1.46 Balance at December 31, 2015 3,166,968 6,053,672 $ 2.13 7.6 $ 20,605 Vested and exercisable at December 31, 2014 2,379,076 $ 0.72 6.8 $ 4,764 Vested and expected to vest at December 31, 2014 3,777,913 $ 0.78 7.5 $ 7,452 Vested and exercisable at December 31, 2015 3,179,361 $ 0.96 6.4 $ 14,451 Vested and expected to vest at December 31, 2015 5,786,950 $ 2.08 7.5 $ 19,990
Schedule of Weighted-Average Assumptions Fair Value of Employee Stock Options Estimated Date of Grant Using Black-Scholes Option-Pricing Model	The fair value of employee stock options was estimated at the date of grant using a Black-Scholes option-pricing model with the following weighted-average assumptions: Year Ended December 31, 2015 2014 2013 Expected term (in years) 5.9 5.7 6.2 Expected volatility (%) 68.7% 50.7% 52.4% Risk-free interest rate (%) 1.8% 1.8% 1.2% Expected dividend yield (%) 0.0% 0.0% 0.0%
Summary of Stock-Based Compensation Expense	Total stock-based compensation expense recognized in the Company’s consolidated statements of operations is classified as follows (in thousands): Year Ended December 31, 2015 2014 2013 Research and development $ 262 $ 85 $ 29 Selling and marketing 50 15 9 General and administrative 754 218 181 Total stock-based compensation expense $ 1,066 $ 318 $ 219

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule of Reconciliation of Differences Between Income Taxes	The following reconciles the differences between income taxes computed at the federal income tax rate and the provision for income taxes: Year Ended December 31, 2015 2014 2013 Expected income tax benefit at the federal statutory rate 34.0 % 34.0 % 34.0 % State taxes, net of federal benefit (0.8 ) 3.7 1.5 Change in effective tax rate (0.9 ) 1.3 0.0 Non-deductible items and other (0.5 ) 0.4 (2.1 ) Federal and state credits (0.7 ) 1.2 2.0 Change in valuation allowance (31.10 ) (40.60 ) (35.40 ) Total 0.0 % 0.0 % 0.0 %
Schedule of Deferred Tax Assets	The principal components of the Company’s net deferred tax assets consisted of the following at December 31, 2015 and 2014 (in thousands): Year Ended December 31, 2015 2014 Net operating loss carryforwards $ 60,979 $ 46,024 Research and development tax credits 1,731 2,441 Reserves and accruals 966 724 Other 2,433 2,948 Total deferred tax assets 66,109 52,137 Valuation allowance (66,109 ) (52,137 ) Net deferred tax assets $ — $ —
Schedule of Unrecognized Tax Benefits	At December 31, 2015 and 2014, the Company’s unrecognized tax benefits consist of the following: Year Ended December 31, 2015 2014 Unrecognized tax benefit, beginning of period $ — $ — Gross increases — current year tax positions 130 — Gross decreases — current year tax positions — — Gross increases — prior year tax positions 612 — Unrecognized tax benefit, end of period $ 742 $ —

Net Loss per Share (Tables)

Net Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Computation of Company's Basic and Diluted Net Loss Per Share	The following table sets forth the computation of the Company’s basic and diluted net loss per share for the periods presented (in thousands, except share and per share data): Year Ended December 31, 2015 2014 2014 Net loss $ (44,995 ) $ (33,800 ) $ (27,222 ) Cumulative dividends on convertible preferred stock — — (2,898 ) Deemed capital contribution on conversion of Series C convertible preferred stock into common stock — — 8,783 Deemed dividend on convertible preferred stock extinguishment — — (6,863 ) Deemed capital contribution on repurchase of Series A preferred stock — 9 — Net loss attributable to common stockholders $ (44,995 ) $ (33,791 ) $ (28,200 ) Weighted-average common shares used in computing net loss per share, basic and diluted 17,432,434 892,315 815,340 Net loss per share, basic and diluted $ (2.58 ) $ (37.87 ) $ (34.59 )
Anti-Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share	The following weighted-average common stock equivalents were excluded from the calculation of diluted net loss per share for the periods presented because including them would have had an anti-dilutive effect: Year Ended December 31, 2015 2014 2013 Convertible preferred stock (if converted) 16,558,330 25,078,396 20,901,591 Options to purchase common stock 5,032,768 3,766,704 2,799,118 Convertible preferred stock warrant 71,318 128,231 5,619 Common stock warrant 142,513 — —

Segment and Geographic Inform40

Segment and Geographic Information (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Summary of Revenue by Geographic Area on the Customers Location	The following table sets forth revenue by geographic area on the customers’ location (in thousands): Year ended December 31, 2015 2014 2013 United States $ 5,332 $ 6,399 $ 3,159 Korea 4,988 — — Rest of world 70 — — Total revenue $ 10,390 $ 6,399 $ 3,159

Background and Organization - A

Background and Organization - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Background And Organization [Line Items]
Net loss from operations	$ (44,995)	$ (33,800)	$ (27,222)
Net cash used from operations	(39,849)	$ (27,469)	$ (25,371)
Scenario Plan
Background And Organization [Line Items]
Additional working capital	$ 15,000

Summary of Significant Accoun42

Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 31, 2015
Significant Accounting Policies [Line Items]
Restricted cash		$ 943,000	$ 1,053,000
Allowances for doubtful accounts		0	0
Inventory lower of cost and market adjustment		2,578,000	598,000	$ 4,582,000
Impairment loss recognized		0	0	$ 0
Deferred offering costs		0	1,419,000
Wrote off deferred offering costs	$ 2,900,000
Reserve for deferred costs of revenue		$ 0	0
Excise tax on medical devices		2.30%
Deferred commission		$ 799,000	221,000
Penalties and interest related to income taxes		0
Asset Retirement Obligation
Significant Accounting Policies [Line Items]
Asset retirement obligation		258,000			$ 250,000
Accretion expenses		$ 8,000
Software
Significant Accounting Policies [Line Items]
Property and equipment, useful life		3 years
License Cost
Significant Accounting Policies [Line Items]
Estimated useful life		3 years
Minimum
Significant Accounting Policies [Line Items]
Property and equipment, useful life		2 years
Minimum | Patents
Significant Accounting Policies [Line Items]
Estimated useful life		5 years
Maximum
Significant Accounting Policies [Line Items]
Property and equipment, useful life		15 years
Maximum | Patents
Significant Accounting Policies [Line Items]
Estimated useful life		7 years
Irrevocable Standby Letters of Credit
Significant Accounting Policies [Line Items]
Letters of credit drawn, amount		$ 0	$ 0

Summary of Significant Accoun43

Summary of Significant Accounting Policies - Schedule of Customers Representing Greater than 10% of Accounts Receivable and Revenue (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue | Customer Concentration Risk | Customer A
Concentration Risk [Line Items]
Percentage of concentration risk			72.00%
Revenue | Customer Concentration Risk | Customer B
Concentration Risk [Line Items]
Percentage of concentration risk		52.00%
Revenue | Customer Concentration Risk | Customer C
Concentration Risk [Line Items]
Percentage of concentration risk		40.00%
Revenue | Customer Concentration Risk | Customer D
Concentration Risk [Line Items]
Percentage of concentration risk	48.00%
Revenue | Customer Concentration Risk | Customer E
Concentration Risk [Line Items]
Percentage of concentration risk	43.00%
Revenue | Geographic Concentration Risk | State of Ohio
Concentration Risk [Line Items]
Percentage of concentration risk			28.00%
Accounts Receivable | Customer Concentration Risk | Customer D
Concentration Risk [Line Items]
Percentage of concentration risk		100.00%
Accounts Receivable | Customer Concentration Risk | Customer E
Concentration Risk [Line Items]
Percentage of concentration risk	94.00%

Summary of Significant Accoun44

Summary of Significant Accounting Policies - Schedule of Depreciation and Amortization Periods for Property and Equipment (Detail)	12 Months Ended
	Dec. 31, 2015
Minimum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	2 years
Maximum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	15 years
Prototype
Property Plant And Equipment [Line Items]
Property and equipment, useful life	2 years
Machinery and Equipment | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	5 years
Machinery and Equipment | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	15 years
Furniture and Fixtures | Minimum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	5 years
Furniture and Fixtures | Maximum
Property Plant And Equipment [Line Items]
Property and equipment, useful life	10 years
Software
Property Plant And Equipment [Line Items]
Property and equipment, useful life	3 years
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and Equipment, Estimated Useful Life	Lesser of estimated useful life or remaining lease term

Merger - Additional Information

Merger - Additional Information (Details) $ / shares in Units, $ in Millions	Jul. 23, 2015USD ($)$ / sharesshares	Dec. 31, 2015shares	Dec. 31, 2014shares	Dec. 31, 2013shares
Business Acquisition [Line Items]
Common stock, shares authorized	300,000,000	90,000,000	88,000,000
Reverse stock split, description		July 23, 2015, ViewRay Technologies, Inc. effected a 2.975-for-1 stock split of its then outstanding common stock and convertible preferred stock, collectively referred to as Capital Stock, and convertible preferred stock warrants, in which (i) each share of outstanding Capital Stock was increased into 2.975 shares of Capital Stock; (ii) the number of outstanding options to purchase each Capital Stock was proportionately increased on a 2.975-for-1 basis; (iii) number of shares reserved for future option grants under the 2008 Plan were proportionately increased on a 2.975-for-1 basis; (iv) the exercise price of each such outstanding option was proportionately decreased on a 2.975-for-1 basis; and (v) each share of outstanding convertible preferred stock warrant was increased into 2.975 shares of convertible preferred stock warrant. All of the share and per share amounts have been adjusted, on a retroactive basis, to reflect this 2.975-for-1 stock split.
Reverse stock split, conversion ratio	2.975
Common stock, shares outstanding		38,204,960	907,037
Common stock reserved for issuance		9,833,252	32,326,764
Options to purchase shares granted to employees		1,975,673	1,642,799	1,190,349
2008 Stock and 2015 Equity Incentive Plan
Business Acquisition [Line Items]
Percentage of common stock on diluted basis	19.30%
Common stock reserved for issuance	9,225,397
2015 Equity Incentive Plan
Business Acquisition [Line Items]
Options to purchase shares granted to employees	1,507,147
2015 Employee Stock Purchase Plan
Business Acquisition [Line Items]
Common stock reserved for issuance	285,621	285,621
Former Holders Of View Ray Technologies, Inc
Business Acquisition [Line Items]
Common stock, shares outstanding	34,715,582
Percentage of stock owned by former stockholders	72.70%
Convertible warrants	128,231
Percentage of common stock warrants on diluted basis	0.30%
Placement Agents
Business Acquisition [Line Items]
Percentage of common stock on diluted basis	0.40%
Common stock issued as warrants	198,760
Holders of Mirax
Business Acquisition [Line Items]
Common stock, shares outstanding	1,000,005
Percentage of common stock on diluted basis	2.10%
Private Placement
Business Acquisition [Line Items]
Private placement, value | $	$ 26.3
Private placement, common shares	5,884,504
Sales of share common stock, per share | $ / shares	$ 5
Percentage of common stock on diluted basis	12.30%
Private Placement | Investor
Business Acquisition [Line Items]
Private placement, value | $	$ 17
Private Placement | Share Holders of Mirax
Business Acquisition [Line Items]
Common stock, shares outstanding	1,000,005
Private Placement | Majority Shareholder
Business Acquisition [Line Items]
Percentage of stock owned by former stockholders	90.90%
Private Placement | Former Holders Of View Ray Technologies, Inc
Business Acquisition [Line Items]
Private placement, common shares	3,400,003
Private Placement | New Share Holders
Business Acquisition [Line Items]
Private placement, common shares	2,484,501
Blank Check Preferred Stock
Business Acquisition [Line Items]
Preferred stock, shares authorized	10,000,000
Preferred stock, par value | $ / shares	$ 0.01

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 18,185	$ 12,736
Less: accumulated depreciation and amortization	(10,879)	(9,805)
Property and equipment, net	7,306	2,931
Prototype
Property Plant And Equipment [Line Items]
Property and equipment, gross	6,492	6,342
Machinery and Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	7,128	4,214
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,532	1,270
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment, gross	350	263
Software
Property Plant And Equipment [Line Items]
Property and equipment, gross	832	$ 647
Construction In Progress
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 1,851

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Balance Sheet Related Disclosures [Abstract]
Depreciation and amortization	$ 1,100	$ 853	$ 1,100
Amortization of intangible assets	$ 168	$ 167	$ 69

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 604	$ 500
Accumulated amortization	(404)	(236)
Intangible assets, net	200	264
License Cost
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	500	$ 500
Patents
Finite Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 104

Balance Sheet Components - Su49

Balance Sheet Components - Summary of Estimated Future Amortization Expense (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Balance Sheet Related Disclosures [Abstract]
2,016	$ 115
2,017	18
2,018	18
2,019	18
2,020	18
Thereafter	13
Intangible assets, net	$ 200	$ 264

Balance Sheet Components - Sc50

Balance Sheet Components - Schedule of Accrued Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Accrued payroll and related benefits	$ 1,938	$ 1,652
Accrued accounts payable	1,880	143
Sales tax and medical device excise tax payable	219	499
Accrued legal and accounting	857	901
Accrued interest	0	142
Other	519	296
Total accrued liabilities	$ 5,413	$ 3,633

Balance Sheet Components - Sc51

Balance Sheet Components - Schedule of Deferred Revenue (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred Revenue [Line Items]
Total deferred revenue	$ 5,961	$ 7,361
Less: current portion of deferred revenue	(5,616)	(7,361)
Noncurrent portion of deferred revenue	345	0
Product
Deferred Revenue [Line Items]
Total deferred revenue	5,050	6,919
Services
Deferred Revenue [Line Items]
Total deferred revenue	$ 911	$ 442

Fair Value of Financial Instr52

Fair Value of Financial Instruments - Additional Information (Detail) $ in Thousands	Jul. 23, 2015USD ($)
Fair Value Disclosures [Abstract]
Convertible preferred stock warrant liability	$ 93

Fair Value of Financial Instr53

Fair Value of Financial Instruments - Schedule of Fair Value of Financial Liabilities (Detail) - Convertible Preferred Stock Warrant Liability $ in Thousands	Dec. 31, 2014USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible preferred stock warrant liability	$ 138
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible preferred stock warrant liability	$ 138

Fair Value of Financial Instr54

Fair Value of Financial Instruments - Summary of Changes in Fair Value of Level 3 Financial Liabilities (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Fair value, beginning of period	$ 138	$ 158	$ 0
Issuance of convertible preferred stock warrant	0	0	158
Change in fair value of Level 3 financial liabilities	(45)	(20)	0
Fair value, end of period	$ 93	$ 138	$ 158

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)	Jun. 26, 2015	Nov. 30, 2014	Aug. 31, 2014	Mar. 26, 2016	Dec. 31, 2015	Dec. 31, 2014	Mar. 31, 2016	Mar. 21, 2016	Dec. 31, 2013	Dec. 31, 2008
Debt Instrument [Line Items]
Debt instrument, interest rate percentage										6.00%
Convertible preferred stock warrant liability					$ 0	$ 138,000
Debt maturity date					Dec. 31, 2009
Proceeds from issuance of convertible notes, net						9,941,000
Conversion of convertible notes into new Series C convertible preferred stock						10,129,000
Series C Convertible Preferred Stock
Debt Instrument [Line Items]
Exercise price					$ 5.08
Hercules Term Loan
Debt Instrument [Line Items]
Amount outstanding under the agreement						$ 15,000,000
Stated Percentage Rate Range, Maximum						10.25%
Maturity Date Range, End					Jun. 1, 2017
Unamortized debt discount					$ 466,000
Beginning period for interest payments					Jan. 1, 2015
Frequency of Periodic Payment					Monthly principal and interest payments
Beginning period for interest payments					Jan. 31, 2014
Exercisable from Issuance					10 years
Exercisable after an IPO					5 years
Convertible preferred stock warrant liability					$ 158,000
Fair value of warrant assumption, expected term					2 years
Fair value of warrant assumption, expected volatility					30.00%
Fair value of warrant assumption, risk-free interest rate					0.40%
Fair value of warrant assumption, expected dividend yield					0.00%
Hercules Term Loan | Series C Convertible Preferred Stock
Debt Instrument [Line Items]
Vested and exercisable warrant to purchase					128,231
Exercise price					$ 5.84
Hercules Term Loan | First 12 months
Debt Instrument [Line Items]
Prepayment penalty					5.00%
Hercules Term Loan | Thereafter Until Maturity
Debt Instrument [Line Items]
Prepayment penalty					1.00%
Hercules Term Loan | Prime Rate
Debt Instrument [Line Items]
Spread on interest rate					7.00%
CRG Term Loan
Debt Instrument [Line Items]
Frequency of Periodic Payment					Quarterly
Maximum borrowing capacity	$ 50,000,000
Current borrowing capacity	30,000,000
Remaining borrowing capacity	20,000,000
Debt drawn	$ 30,000,000
Debt maturity date					Jun. 26, 2020
Line of credit facility, covenant terms					On March 24, 2016, the Company and CRG executed an amendment to the original terms of the CRG Term Loan such that, with regard to the conditions for borrowing the remaining $20.0 million available under the CRG Term Loan, the Company may, at its election, draw down (i) an amount of either $10.0 million or $15.0 million in up to two advances upon achievement of a minimum of $15.0 million of aggregate product and service revenue during any consecutive 12 month period ending on or before March 31, 2016 and (ii) an additional $5.0 million (or $10.0 million, if the previous draw made was only in an amount of $10.0 million) upon achievement of a minimum of $25.0 million of aggregate product and service revenue during any consecutive 12 month period ending on or before December 31, 2016 and upon execution of the first sales contract of the Company’s second generation product.
Facility fee	7.00%
CRG Term Loan | Subsequent Event
Debt Instrument [Line Items]
Proceeds from term loan				$ 40,000,000
Post Money Valuation Minimum Amount							$ 120,000,000
CRG Term Loan | Subsequent Event | Milestone One
Debt Instrument [Line Items]
Remaining borrowing capacity							10,000,000
Debt drawn								$ 10,000,000
Required minimum gross revenue							15,000,000
CRG Term Loan | Subsequent Event | Milestone Two
Debt Instrument [Line Items]
Remaining borrowing capacity							5,000,000
Debt drawn								$ 15,000,000
Required minimum gross revenue							$ 25,000,000
CRG Term Loan | First 12 months
Debt Instrument [Line Items]
Debt instrument, interest rate percentage	12.50%
Prepayment penalty	3.00%
Debt instrument cash interest rate percentage	8.00%
Deferred payment in-kind interest rate	4.50%
CRG Term Loan | After Year 1 but on or Before Year 2
Debt Instrument [Line Items]
Debt instrument, interest rate percentage	12.50%
Prepayment penalty	2.00%
Debt instrument cash interest rate percentage	8.00%
Deferred payment in-kind interest rate	4.50%
CRG Term Loan | After Year 2 but on or Before Year 3
Debt Instrument [Line Items]
Debt instrument, interest rate percentage	12.50%
Prepayment penalty	1.00%
CRG Term Loan | After Year 3 Thereafter Until Maturity
Debt Instrument [Line Items]
Prepayment penalty	0.00%
2014 Convertible Promissory Notes
Debt Instrument [Line Items]
Aggregate principal amount			$ 10,000,000
Additional borrowing capacity			1,500,000
Proceeds from issuance of convertible notes, net		$ 6,100,000	$ 3,900,000
Interest rate					8.00%
Maturity date					2015-11
Conversion of convertible notes into new Series C convertible preferred stock					$ 10,200,000
Longer outstanding					0
Debt instrument available for issuance					0
2014 Convertible Promissory Notes | Series C Convertible Preferred Stock
Debt Instrument [Line Items]
Unamortized debt discount					$ 0	$ 44,000			$ 0
Exercise price					$ 5.84
Stock issued convertible debt					1,739,405	1,739,405
Deferred Payment In-Kind Interest | Hercules Term Loan
Debt Instrument [Line Items]
Debt instrument, interest rate percentage					1.50%

Debt - Scheduled Future Payment

Debt - Scheduled Future Payments on Term Loan (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Less: current portion	$ 0	$ (5,493)
Long-term debt, net of current portion	29,016	$ 9,149
CRG Term Loan
Debt Instrument [Line Items]
2,016	2,541
2,017	2,652
2,018	12,019
2,019	19,644
2020 and thereafter	10,506
Total future payments	47,362
Less: amount representing interest and end-of-term facility fee	(17,362)
Amount outstanding under the agreement	30,000
Less: unamortized debt discount	(984)
Carrying value of long-term debt	29,016
Less: current portion	0
Long-term debt, net of current portion	$ 29,016

Commitments and Contingencies -

Commitments and Contingencies - Schedule of Future Minimum Lease Payments Under Non-cancelable Operating Lease Agreements (Detail) $ in Thousands	Dec. 31, 2015USD ($)
Operating Leases Future Minimum Payments Due [Abstract]
2,016	$ 1,113
2,017	1,106
2,018	963
2,019	823
Total future minimum payments	$ 4,005

Commitments and Contingencies58

Commitments and Contingencies - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments And Contingencies Disclosure [Abstract]
Rent expense	$ 1,300,000	$ 683,000	$ 308,000
Purchase commitments	$ 0	$ 0

Licensing - Additional Informat

Licensing - Additional Information (Detail) - Licensing Agreements - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2004
Licenses Agreements [Line Items]
Common Stock granted in exchange for licensing					33,652
Milestone description		ViewRay Technologies, Inc. met all of the product development and commercialization milestones at December 31, 2013 and started to make quarterly royalty payments in 2014.
Percentage of royalty payment based on net sale		1.00%
Cost of Sales
Licenses Agreements [Line Items]
Royalty Expense		$ 102,000	$ 137,000	$ 26,000
General and Administrative
Licenses Agreements [Line Items]
Royalty Expense		$ 49,000	$ 63,000	$ 0
Minimum
Licenses Agreements [Line Items]
Quarterly royalty payment	$ 50,000

Grant Revenue - Additional Info

Grant Revenue - Additional Information (Detail) - USD ($)	Jul. 31, 2010	Apr. 30, 2009	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2008
Government Grant [Line Items]
Maximum borrowing capacity under the agreement						$ 800,000
Stated interest rate						6.00%
Debt maturity date			Dec. 31, 2009
Debt description			Under the terms of the loan agreement, the lender may forgive $240 thousand if the Company meets certain permanent job creation requirements within the State of Ohio. In July 2010, $560 thousand of principal and accrued interest through the loan maturity date were repaid. In September 2015, the remaining $240 thousand was forgiven and was recognized as grant revenue during the year ended December 31, 2015.
Repayment of debt	$ 560,000
Grants awarded from state of Ohio			$ 240,000	$ 0	$ 894,000
State of Ohio | ViewRay
Government Grant [Line Items]
Grants awarded from state of Ohio		$ 2,800,000
State of Ohio | Maximum
Government Grant [Line Items]
Grants awarded from state of Ohio		$ 5,000,000

Distribution Agreement - Additi

Distribution Agreement - Additional Information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended
	Feb. 28, 2015USD ($)$ / shares	Jan. 31, 2015USD ($)$ / shares	Dec. 31, 2014USD ($)Installment$ / shares	Dec. 31, 2015USD ($)$ / shares	Nov. 30, 2013$ / shares
Marketing Agreement [Line Items]
Customer deposits			$ 6,100	$ 12,763
Series C Convertible Preferred Stock
Marketing Agreement [Line Items]
Stock issued value	$ 15,000	$ 950
Stock price | $ / shares	$ 5.84	$ 5.84		$ 5.84	$ 5.84
Itochu Corporation Agreement
Marketing Agreement [Line Items]
Distribution fees			$ 4,000
Number of installments | Installment			3
Distribution agreement term			10 years
Itochu Corporation Agreement | Series C Convertible Preferred Stock
Marketing Agreement [Line Items]
Stock issued value			$ 5,200
Stock price | $ / shares			$ 5.84
Itochu Corporation Agreement | First Installment
Marketing Agreement [Line Items]
Distribution fees			$ 1,000
Customer deposits			1,000
Itochu Corporation Agreement | Second Installment
Marketing Agreement [Line Items]
Distribution fees			1,000
Customer deposits				$ 1,000
Itochu Corporation Agreement | Third Installment
Marketing Agreement [Line Items]
Distribution fees			$ 2,000

Common Stock Reserved for Iss62

Common Stock Reserved for Issuance - Schedule of Common Stock Reserved for Future Issuance (Detail) - shares	Dec. 31, 2015	Dec. 31, 2014
Class Of Stock [Line Items]
Total shares of common stock reserved	9,833,252	32,326,764
Convertible Preferred Stock
Class Of Stock [Line Items]
Total shares of common stock reserved		27,654,928
Shares available for future stock option grants
Class Of Stock [Line Items]
Total shares of common stock reserved	3,166,968	295,101
ESPP shares available for issuance
Class Of Stock [Line Items]
Total shares of common stock reserved	285,621
Warrant to purchase convertible preferred stock
Class Of Stock [Line Items]
Total shares of common stock reserved		128,231
Warrant to purchase common stock
Class Of Stock [Line Items]
Total shares of common stock reserved	326,991
Options To Purchase Common Stock
Class Of Stock [Line Items]
Total shares of common stock reserved	6,053,672	4,248,504

Convertible Preferred Stock - A

Convertible Preferred Stock - Additional Information (Detail) $ / shares in Units, $ in Thousands	1 Months Ended					2 Months Ended	12 Months Ended
	Feb. 28, 2015USD ($)$ / sharesshares	Jan. 31, 2015USD ($)$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Nov. 30, 2013USD ($)$ / sharesshares	Feb. 28, 2013USD ($)$ / sharesshares	Jun. 30, 2013USD ($)$ / sharesshares	Dec. 31, 2015USD ($)Director$ / sharesshares	Dec. 31, 2014USD ($)$ / sharesshares	Dec. 31, 2013USD ($)shares	Jul. 23, 2015shares
Convertible Preferred Stock [Line Items]
Proceeds from issuance of Convertible preferred stock | $							$ 15,729	$ 4,969	$ 34,860
Accrued dividends | $						$ 1,400
Number of convertible preferred stock converted to common stock | shares										30,381,987
Preferred stock conversion rate										100.00%
Number of board of directors | Director							8
Number of members separate class of stockholders are entitled to elect | Director							7
Net proceeds from public offering | $							$ 50,000
Per annum rate for cash dividend							8.00%
Description of order of preference							Such payments were to be paid in order of preference (Series D-1, Series C, Series B-1 convertible preferred stock).
Cash dividends, percent							8.00%
Original issue price							$ 3.99
Convertible preferred stock remained outstanding, percentage							20.00%
Proceeds from conversion, per share							$ 17.55
Proceeds from conversion | $							$ 50,000
IPO
Convertible Preferred Stock [Line Items]
Public offering, per share							$ 15.25
Convertible Preferred Stock
Convertible Preferred Stock [Line Items]
Convertible preferred stock, shares issued | shares							2,727,059	880,546	2,564,638
Stock issued convertible debt | shares							(30,381,987)	1,739,405	22,308,230
Common Stock
Convertible Preferred Stock [Line Items]
Stock issued convertible debt | shares							30,381,987
Number of members separate class of stockholders are entitled to elect | Director							2
Series D-1 Convertible Preferred Stock
Convertible Preferred Stock [Line Items]
Proceeds from issuance of Convertible preferred stock | $					$ 5,000
Convertible preferred stock, shares issued | shares					983,558
Preferred stock, shares issued, price per share					$ 5.08
Public offering, per share							$ 5.08
Description of order of preference							Equal to the sum of $5.08 per share plus any accrued but unpaid dividends
Cash dividends, percent							8.00%
Original issue price							$ 5.08
Series D-2 Convertible Preferred Stock | Convertible Preferred Stock
Convertible Preferred Stock [Line Items]
Convertible preferred stock, shares issued | shares						3,013,797
Preferred stock, shares issued, price per share						$ 5.08
Issuance of convertible preferred stock | $						$ 15,300
Stock issued convertible debt | shares						3,196,417			3,196,417
Series C Convertible Preferred Stock
Convertible Preferred Stock [Line Items]
Proceeds from issuance of Convertible preferred stock | $				$ 15,000
Convertible preferred stock, shares issued | shares	2,564,652	162,407	2,619,951	2,564,638
Preferred stock, shares issued, price per share	$ 5.84	$ 5.84		$ 5.84			$ 5.84
Issuance of convertible preferred stock | $	$ 15,000	$ 950
Common stock, exchange basis						10.00%
Gain (loss) on extinguishment of Series C convertible preferred stock | $						$ 8,800
Number of members separate class of stockholders are entitled to elect | Director							1
Public offering, per share							$ 5.08
Cash dividends, percent							8.00%
Share conversion price							$ 5.84
Convertible preferred stock, liquidation preference							$ 5.84
Series C Convertible Preferred Stock | 2014 Convertible Promissory Notes
Convertible Preferred Stock [Line Items]
Stock issued convertible debt | shares							1,739,405	1,739,405
Public offering, per share							$ 5.84
Series C Convertible Preferred Stock | Itochu Corporation Agreement
Convertible Preferred Stock [Line Items]
Convertible preferred stock, shares issued | shares			880,546
Preferred stock, shares issued, price per share			$ 5.84					$ 5.84
Issuance of convertible preferred stock | $			$ 5,200
Series C Convertible Preferred Stock | Convertible Preferred Stock
Convertible Preferred Stock [Line Items]
Stock issued convertible debt | shares						1,470,485			(1,470,485)
Series C Convertible Preferred Stock | Convertible Preferred Stock | 2014 Convertible Promissory Notes
Convertible Preferred Stock [Line Items]
Stock issued convertible debt | shares								1,739,405
Series C Convertible Preferred Stock | Common Stock
Convertible Preferred Stock [Line Items]
Stock issued convertible debt | shares						147,051			147,051
Series B Convertible Preferred Stock [Member]
Convertible Preferred Stock [Line Items]
Preferred stock, shares issued, price per share							5.08
Gain (loss) on extinguishment of Series C convertible preferred stock | $						$ (6,900)
Public offering, per share							$ 3.99
Description of order of preference							Equal to the sum of $3.99 per share plus any declared but unpaid dividends on such shares
Cash dividends, percent							8.00%
Share conversion price							$ 5.08
Convertible preferred stock, liquidation preference							5.08
Series B Convertible Preferred Stock [Member] | Convertible Preferred Stock
Convertible Preferred Stock [Line Items]
Stock issued convertible debt | shares									22,308,230
Series A Convertible Preferred Stock
Convertible Preferred Stock [Line Items]
Preferred stock, shares issued, price per share							$ 3.99
Number of members separate class of stockholders are entitled to elect | Director							1
Conversion price, per share							$ 3.99
Description of order of preference							$18.52 per share plus any declared but unpaid dividends on such shares
Convertible preferred stock, liquidation preference							$ 18.52
Series A Convertible Preferred Stock | Convertible Preferred Stock
Convertible Preferred Stock [Line Items]
Stock issued convertible debt | shares							(162,109)
Series B1 Preferred Stock
Convertible Preferred Stock [Line Items]
Public offering, per share							$ 3.99

Convertible Preferred Stock - C

Convertible Preferred Stock - Changes in Shares of Convertible Preferred Stock and Common Stock (Detail) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Class Of Stock [Line Items]
Temporary equity balance , shares	27,654,928
Issuance of common stock from option exercises, shares	31,427	28,320	1,463
Temporary equity balance , shares		27,654,928
Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary equity balance , shares	162,109
Temporary equity balance , shares		162,109
Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary equity balance , shares	27,654,928	25,036,330	16,748,405
Repurchase of Series A convertible preferred stock and deemed capital contribution		(1,353)
Stock issued convertible debt	(30,381,987)	1,739,405	22,308,230
Convertible preferred stock, shares issued	2,727,059	880,546	2,564,638
Extinguishment of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock			(22,308,230)
Temporary equity balance , shares		27,654,928	25,036,330
Convertible Preferred Stock | Series A Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary equity balance , shares	162,109	163,462	163,462
Repurchase of Series A convertible preferred stock and deemed capital contribution		(1,353)
Stock issued convertible debt	(162,109)
Temporary equity balance , shares		162,109	163,462
Convertible Preferred Stock | Extinguished Series B-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary equity balance , shares			6,321,238
Extinguishment of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock			(6,321,238)
Convertible Preferred Stock | Extinguished Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary equity balance , shares			9,108,533
Extinguishment of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock			(7,638,048)
Convertible Preferred Stock | Extinguished Series D-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary equity balance , shares			1,155,172
Extinguishment of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock			(2,138,730)
Convertible Preferred Stock | Extinguished Series D-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Extinguishment of Series B-1, Series C, Series D-1 and Series D-2 convertible preferred stock			(6,210,214)
Convertible Preferred Stock | New Series B Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary equity balance , shares	22,308,230	22,308,230
Stock issued convertible debt	(22,308,230)		22,308,230
Temporary equity balance , shares		22,308,230	22,308,230
Convertible Preferred Stock | New Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Temporary equity balance , shares	5,184,589	2,564,638
Stock issued convertible debt	(7,911,648)	1,739,405
Convertible preferred stock, shares issued	2,727,059	880,546	2,564,638
Temporary equity balance , shares		5,184,589	2,564,638
Convertible Preferred Stock | Series D-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares issued			983,558
Convertible Preferred Stock | Series D-1 Convertible Preferred Stock | Extinguished Series D-1 Convertible Preferred Stock
Class Of Stock [Line Items]
Convertible preferred stock, shares issued			983,558
Convertible Preferred Stock | Series D-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Stock issued convertible debt			3,196,417
Convertible preferred stock, shares issued			3,013,797
Convertible Preferred Stock | Series D-2 Convertible Preferred Stock | Extinguished Series D-2 Convertible Preferred Stock
Class Of Stock [Line Items]
Stock issued convertible debt			3,196,417
Convertible preferred stock, shares issued			3,013,797
Convertible Preferred Stock | Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Stock issued convertible debt			(1,470,485)
Convertible Preferred Stock | Series C Convertible Preferred Stock | Extinguished Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Stock issued convertible debt			(1,470,485)
Common Stock
Class Of Stock [Line Items]
Balance, shares	907,037	878,717	730,203
Stock issued convertible debt	30,381,987
Issuance of common stock from option exercises, shares	31,427	28,320	1,463
Balance, shares	38,204,960	907,037	878,717
Common Stock | Private Placement
Class Of Stock [Line Items]
Convertible preferred stock, shares issued	5,884,504
Common Stock | Holders of Mirax
Class Of Stock [Line Items]
Convertible preferred stock, shares issued	1,000,005
Common Stock | Series C Convertible Preferred Stock
Class Of Stock [Line Items]
Stock issued convertible debt			147,051

Convertible Preferred Stock -65

Convertible Preferred Stock - Components of Convertible Preferred Stock (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	80,710,997	74,460,997
Convertible preferred stock, shares outstanding		27,654,928
Convertible preferred stock, aggregate liquidation preference		$ 146,732
Convertible preferred stock, Net carrying value	$ 0	$ 145,110
Series A Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	398,500	398,500
Convertible preferred stock, shares outstanding		162,109
Convertible preferred stock, aggregate liquidation preference		$ 3,004
Convertible preferred stock, Net carrying value		$ 3,003
Series B Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	60,500,000	60,500,000
Convertible preferred stock, shares outstanding		22,308,230
Convertible preferred stock, aggregate liquidation preference		$ 113,405
Convertible preferred stock, Net carrying value		$ 112,080
Series C Convertible Preferred Stock
Temporary Equity [Line Items]
Convertible preferred stock, shares authorized	19,812,497	13,562,497
Convertible preferred stock, shares outstanding		5,184,589
Convertible preferred stock, aggregate liquidation preference		$ 30,323
Convertible preferred stock, Net carrying value		$ 30,027

Warrants - Additional Informati

Warrants - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	Dec. 31, 2013	Aug. 31, 2015	Jul. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jul. 23, 2015
Convertible Preferred Stock Warrants [Line Items]
Convertible preferred stock warrant liability	$ 158			$ 93
Change in the fair value of the warrant				(45)	$ (20)
Estimated fair value of the warrants issued to placement agents				$ 316
Insiders
Convertible Preferred Stock Warrants [Line Items]
Common stock issued as warrants		198,760	198,760
Common stock issued as warrants, exercise per share		$ 5	$ 5
Common stock warrants, expiry term		5 years	5 years
Term Loan | Series C Convertible Preferred Stock
Convertible Preferred Stock Warrants [Line Items]
Vested and exercisable warrant to purchase	128,231					128,231	128,231

Warrants - Summary of Assumptio

Warrants - Summary of Assumptions to Use Option Pricing Model (Detail)	Jul. 23, 2015	Dec. 31, 2015	Dec. 31, 2014
Series Convertible Preferred Stock Warrant
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Expected term (in years)	5 years		5 years 3 months 18 days
Expected volatility (%)	31.80%		30.00%
Risk-free interest rate (%)	1.70%		1.70%
Expected dividend yield (%)	0.00%		0.00%
Common Stock Warrant
Fair Value Inputs Liabilities Quantitative Information [Line Items]
Expected term (in years)		5 years
Expected volatility (%)		31.80%
Risk-free interest rate (%)		1.60%
Expected dividend yield (%)		0.00%

Stock-Based Compensation - Addi

Stock-Based Compensation - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2008	Jul. 23, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option grant, description	Options granted may be either incentive stock options or nonstatutory stock options.
Common stock reserved for issuance	9,833,252	32,326,764
Grant date fair value of options vested, per share	$ 3.13	$ 0.42	$ 0.35
Grant date fair value of options vested	$ 782,000	$ 339,000	$ 72,000
Unrecognized compensation cost	$ 5,200,000
Weighted average period for recognition of compensation costs	3 years 2 months 12 days
Stock-based compensation expense capitalized	$ 0	$ 0	$ 0
Two Thousand Eight Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period of stock option plan	10 years
Two Thousand Eight Stock Option Plan [Member] | Nonstatutory Options [Member] | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of fair value of common stock, percentage	85.00%
Two Thousand Eight Stock Option Plan [Member] | Ten Percent Stockholder [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expiration period of stock option plan	5 years
Two Thousand Eight Stock Option Plan [Member] | Ten Percent Stockholder [Member] | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Exercise price of fair value of common stock, percentage	110.00%
2015 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance	285,621				285,621
Shares issued under ESPP	0
Two Thousand Eight Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option issued				38,059
Stock option issued, exercise price				$ 0.80
Stock option vesting period				3 years
Stock option expiration period				Sep. 30, 2014

Stock-Based Compensation - Summ

Stock-Based Compensation - Summary of Company's Stock Option Activity and Related Information (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Shares Available for Grant
Shares Available for Grant, Beginning balance	295,101	1,848,367	306,097
Shares Available for Grant, Additional shares authorized	4,708,447		2,359,662
Shares Available for Grant, Granted	(1,975,673)	(1,642,799)	(1,190,349)
Shares Available for Grant, Cancelled	139,093	89,533	372,957
Shares Available for Grant, Ending balance	3,166,968	295,101	1,848,367	306,097
Number of Stock Options Outstanding
Number of Stock Options Outstanding, Beginning balance	4,248,519	2,723,573	1,907,644
Number of Stock Options Outstanding, Granted	1,975,673	1,642,799	1,190,349
Number of Stock Options Outstanding, Exercised	(31,427)	(28,320)	(1,463)
Number of Stock Options Outstanding, Cancelled	(139,093)	(89,533)	(372,957)
Number of Stock Options Outstanding, Ending balance	6,053,672	4,248,519	2,723,573	1,907,644
Number of Stock Options Outstanding, Vested and exercisable	3,179,361	2,379,076
Number of Stock Options Outstanding, Vested and expected to vest	5,786,950	3,777,913
Weighted- Average Exercise Price
Weighted- Average Exercise Price, Beginning balance	$ 0.76	$ 0.71	$ 0.71
Weighted- Average Exercise Price, Granted	5.03	0.84	0.70
Weighted- Average Exercise Price, Exercised	0.76	0.73	0.68
Weighted- Average Exercise Price, Cancelled	1.46	0.74	0.69
Weighted- Average Exercise Price, Ending balance	2.13	0.76	$ 0.71	$ 0.71
Weighted- Average Exercise Price, Vested and exercisable	0.96	0.72
Weighted- Average Exercise Price, Vested and expected to vest	$ 2.08	$ 0.78
Weighted- Average Remaining Contractual Life (Years)
Options Outstanding, Weighted- Average Remaining Contractual Life (Years)	7 years 7 months 6 days	7 years 8 months 12 days		6 years 3 months 18 days
Weighted- Average Remaining Contractual Life (Years), Vested and exercisable		6 years 9 months 18 days
Weighted- Average Remaining Contractual Life (Years), Vested and expected to vest		7 years 6 months
Aggregate Intrinsic Value
Aggregate Intrinsic Value	$ 20,605	$ 8,343	$ 138	$ 28
Aggregate Intrinsic Value, Vested and exercisable	14,451	4,764
Aggregate Intrinsic Value, Vested and expected to vest	$ 19,990	$ 7,452

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Weighted-Average Assumptions Fair Value of Employee Stock Options Estimated Date of Grant Using Black-Scholes Option-Pricing Model (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected term (in years)	5 years 10 months 24 days	5 years 8 months 12 days	6 years 2 months 12 days
Expected volatility (%)	68.70%	50.70%	52.40%
Risk-free interest rate (%)	1.80%	1.80%	1.20%
Expected dividend yield (%)	0.00%	0.00%	0.00%

Stock-Based Compensation - Su71

Stock-Based Compensation - Summary of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 1,066	$ 318	$ 219
Research and Development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	262	85	29
Selling and Marketing
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	50	15	9
General and Administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Stock-based compensation expense	$ 754	$ 218	$ 181

Income Tax Reconciliation (Deta

Income Tax Reconciliation (Detail)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Effective Income Tax Rate Continuing Operations Tax Rate Reconciliation [Abstract]
Expected income tax benefit at the federal statutory rate	34.00%	34.00%	34.00%
State taxes, net of federal benefit	(0.80%)	3.70%	1.50%
Change in effective tax rate	(0.90%)	1.30%	0.00%
Non-deductible items and other	(0.50%)	0.40%	(2.10%)
Federal and state credits	(0.70%)	1.20%	2.00%
Change in valuation allowance	(31.10%)	(40.60%)	(35.40%)
Total	0.00%	0.00%	0.00%

Defered Income Tax (Detail)

Defered Income Tax (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Deferred Tax Assets, Net [Abstract]
Net operating loss carryforwards	$ 60,979	$ 46,024
Research and development tax credits	1,731	2,441
Reserves and accruals	966	724
Other	2,433	2,948
Total deferred tax assets	66,109	52,137
Valuation allowance	$ (66,109)	$ (52,137)

Income Tax - Additional Informa

Income Tax - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Income Taxes [Line Items]
Deferred Tax Valuation allowance increase	$ 14	$ 13.7
Research Tax Credit Carryforward
Income Taxes [Line Items]
Federal research and development tax credit carryforwards	2.5
Federal [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 170.1
Operating loss carryforwards, expiration date	Dec. 31, 2024
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	$ 111.8
Operating loss carryforwards, expiration date	Dec. 31, 2019

Unrecognized Tax Benefits (Deta

Unrecognized Tax Benefits (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross increases — current year tax positions	$ 130
Gross increases — prior year tax positions	612
Unrecognized tax benefit, end of period	$ 742

Employee Benefits - Additional

Employee Benefits - Additional information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Compensation And Retirement Disclosure [Abstract]
Description of Defined Contribution Plan	The Company has a 401(k) Plan which covers its eligible employees. The 401(k) Plan permits the participants to defer a portion of their compensation in accordance with the provisions of Section 401(k) of the IRC. At its discretion, the Company can match a portion of the participants’ contributions or make profit-sharing contributions
Defined Contribution Plan, Employer Discretionary Contribution Amount	$ 0	$ 0	$ 0

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Company's Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Net loss	$ (44,995)	$ (33,800)	$ (27,222)
Cumulative dividends on convertible preferred stock	0	0	(2,898)
Deemed capital conversion of Series C convertible preferred stock into common stock	0	0	8,783
Deemed dividend on convertible preferred stock extinguishment	0	0	(6,863)
Deemed capital contribution on repurchase of Series A preferred stock	0	9	0
Net loss attributable to common stockholders	$ (44,995)	$ (33,791)	$ (28,200)
Weighted-average common shares used in computing net loss per share, basic and diluted	17,432,434	892,315	815,340
Net loss per share, basic and diluted	$ (2.58)	$ (37.87)	$ (34.59)

Net Loss Per Share - Anti-Dilut

Net Loss Per Share - Anti-Dilutive Securities Excluded from Calculation of Diluted Net Loss Per Share (Detail) - shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Convertible Preferred Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	16,558,330	25,078,396	20,901,591
Options To Purchase Common Stock
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	5,032,768	3,766,704	2,799,118
Convertible Preferred Stock Warrant
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	71,318	128,231	5,619
Common Stock Warrant
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Anti-dilutive securities excluded from calculation of diluted net loss per share	142,513

Segment and Geographic Inform79

Segment and Geographic Information - Additional Information (Detail)	12 Months Ended
	Dec. 31, 2015Segment
Segment Reporting [Abstract]
Number of reportable segments	1

Segment and Geographic Inform80

Segment and Geographic Information - Summary of Revenue by Geographic Area on the Customers Location (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Entity Wide Revenue Major Customer [Line Items]
Total revenue	$ 10,390	$ 6,399	$ 3,159
Reportable Geographical Components | United States
Entity Wide Revenue Major Customer [Line Items]
Total revenue	5,332	$ 6,399	$ 3,159
Reportable Geographical Components | Korea
Entity Wide Revenue Major Customer [Line Items]
Total revenue	4,988
Reportable Geographical Components | Rest of World
Entity Wide Revenue Major Customer [Line Items]
Total revenue	$ 70