Rockley Photonics (RKLYQ) 10-Q/A 26 Aug 21 2021 Q2 Quarterly report (amended) Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2021	Aug. 12, 2021
Document Information [Line Items]
Document Type	10-Q/A
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2021
Document Transition Report	false
Entity File Number	001-40735
Entity Registrant Name	Rockley Photonics Holdings Limited
Entity Incorporation, State or Country Code	E9
Entity Address, Address Line One	3rd Floor
Entity Address, Address Line Two	1 Ashley Road
Entity Address, City or Town	Altrincham
Entity Address, Country	GB
Entity Address, Postal Zip Code	WA14 2DT
City Area Code	1865
Local Phone Number	292017
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		126,256,257
Entity Central Index Key	0001852117
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q2
Country Region	+44
Ordinary Shares
Document Information [Line Items]
Title of 12(b) Security	Ordinary shares, $0.000004026575398 par value per share
Trading Symbol	RKLY
Security Exchange Name	NYSE
Warrants
Document Information [Line Items]
Title of 12(b) Security	Warrants, each whole warrant exercisable for one ordinary share at an exercise price of $11.50 per share
Trading Symbol	RKLY.WS
Security Exchange Name	NYSE

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Statement - USD ($) $ in Thousands	Jun. 30, 2021	Mar. 11, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents	$ 35,395		$ 19,228
Accounts receivable, net of allowance for doubtful accounts of $377 and $0 as of June 30, 2021 and December 31, 2020, respectively	2,411		4,925
Other receivables	23,037		18,024
Prepaid expenses	7,724		1,605
Other current assets	258		609
Total current assets	68,825		44,391
Property, equipment, and finance lease right-of-use assets, net	8,170		6,182
Equity method investment	4,711		5,202
Intangible assets, net	3,048		3,048
Other non-current assets	11,715		1,607
Total assets	96,469		60,430
Current liabilities
Trade payables	8,692		4,413
Accrued expenses	12,104		10,395
Other current liabilities	1,020		998
Total current liabilities	21,816		15,806
Long-term debt	194,328		74,804
Other long-term liabilities	2,719		1,127
Total liabilities	218,863		91,737
Commitments and contingencies (Note 13)
Shareholders’ deficit
Ordinary shares, $0.00001 par value; 55,982,833 authorized as of June 30, 2021 and December 31, 2020; 33,825,620 and 33,637,762 issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	0		0
Additional paid-in-capital	205,823		201,576
Accumulated deficit	(328,217)		(232,883)
Total Shareholders’ deficit	(122,394)		(31,307)
Total liabilities and Shareholders’ deficit	96,469		$ 60,430
Rockley Photonics Holdings Limited
Current assets
Receivable from affiliate	50	$ 50
Total current assets	50	50
Total assets	50	50
Current liabilities
Commitments and contingencies (Note 13)
Shareholders’ deficit
Ordinary shares and additional paid-in capital (Note 2)	50	50
Total Shareholders’ deficit	$ 50	$ 50

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 377	$ 0
Ordinary shares, par value (in dollars per share)	$ 0.00001	$ 0.00001
Ordinary shares authorized (in shares)	55,982,833	55,982,833
Ordinary shares issued (in shares)	33,825,620	33,637,762
Ordinary shares outstanding (in shares)	33,825,620	33,637,762

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Statement [Abstract]
Revenue	$ 2,195	$ 7,881	$ 3,966	$ 14,544
Cost of revenue	4,549	6,522	8,283	13,085
Gross profit	(2,354)	1,359	(4,317)	1,459
Operating expenses:
Selling, general and administrative expenses	6,715	3,604	14,020	7,249
Research and development expenses	17,551	7,746	33,531	16,217
Total operating expenses	24,266	11,350	47,551	23,466
Loss from operations	(26,620)	(9,991)	(51,868)	(22,007)
Other income (expense):
Forgiveness of Paycheck Protection Program loan	2,860	0	2,860	0
Interest expense, net	(179)	(34)	(326)	(74)
Equity method investment loss	(597)	(102)	(760)	(252)
Change in fair value of debt instruments	(6,008)	312	(45,661)	(2,222)
Gain (loss) on foreign currency	97	(108)	631	(1,654)
Total other income (expense)	(3,827)	68	(43,256)	(4,202)
Loss before income taxes	(30,447)	(9,923)	(95,124)	(26,209)
Provision for income tax	110	80	210	220
Net loss	(30,557)	(10,003)	(95,334)	(26,429)
Comprehensive loss	$ (30,557)	$ (10,003)	$ (95,334)	$ (26,429)
Net loss per share:
Net loss per share, basic (in dollars per share)	$ (0.90)	$ (0.30)	$ (2.82)	$ (0.79)
Net loss per share, diluted (in dollars per share)	$ (0.90)	$ (0.30)	$ (2.82)	$ (0.79)
Weighted-average shares outstanding:
Weighted-average shares outstanding, basic (in shares)	33,922,973	33,625,899	33,850,070	33,554,441
Weighted-average shares outstanding, diluted (in shares)	33,922,973	33,625,899	33,850,070	33,554,441

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Shareholders’ Deficit - USD ($) $ in Thousands	Total	Ordinary Shares	Ordinary Shares and Additional Paid-in Capital	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019		33,337,115
Beginning balance at Dec. 31, 2019	$ 36,259		$ 188,865	$ (152,606)
Increase (Decrease) in Stockholders' Equity
Net loss	(16,426)			(16,426)
Exercise of stock options (in shares)		3,730
Exercise of stock options	20		20
Exercise of warrants (in shares)		5,523
Exercise of warrants	7		7
Stock-based compensation	1,644		1,644
Ordinary share issuance, net of issuance costs (in shares)		147,432
Ordinary share issuance, net of issuance costs	2,087		2,087
Ending balance (in shares) at Mar. 31, 2020		33,493,800
Ending balance at Mar. 31, 2020	23,591		192,623	(169,032)
Beginning balance (in shares) at Dec. 31, 2019		33,337,115
Beginning balance at Dec. 31, 2019	36,259		188,865	(152,606)
Increase (Decrease) in Stockholders' Equity
Net loss	(26,429)
Ending balance (in shares) at Jun. 30, 2020		33,493,800
Ending balance at Jun. 30, 2020	16,007		195,042	(179,035)
Beginning balance (in shares) at Mar. 31, 2020		33,493,800
Beginning balance at Mar. 31, 2020	23,591		192,623	(169,032)
Increase (Decrease) in Stockholders' Equity
Net loss	(10,003)			(10,003)
Stock-based compensation	2,545		2,545
Ordinary share issuance, net of issuance costs	(126)		(126)
Ending balance (in shares) at Jun. 30, 2020		33,493,800
Ending balance at Jun. 30, 2020	16,007		195,042	(179,035)
Beginning balance (in shares) at Dec. 31, 2020		33,637,762
Beginning balance at Dec. 31, 2020	(31,307)		201,576	(232,883)
Increase (Decrease) in Stockholders' Equity
Net loss	(64,777)			(64,777)
Exercise of stock options (in shares)		87,244
Exercise of stock options	137		137
Exercise of warrants (in shares)		23,278
Issuance of warrants	263		263
Stock-based compensation	1,725		1,725
Ending balance (in shares) at Mar. 31, 2021		33,748,284
Ending balance at Mar. 31, 2021	(93,959)		203,701	(297,660)
Beginning balance (in shares) at Dec. 31, 2020		33,637,762
Beginning balance at Dec. 31, 2020	(31,307)		201,576	(232,883)
Increase (Decrease) in Stockholders' Equity
Net loss	$ (95,334)
Exercise of stock options (in shares)	164,580,000
Ending balance (in shares) at Jun. 30, 2021		33,825,620
Ending balance at Jun. 30, 2021	$ (122,394)		205,823	(328,217)
Beginning balance (in shares) at Mar. 31, 2021		33,748,284
Beginning balance at Mar. 31, 2021	(93,959)		203,701	(297,660)
Increase (Decrease) in Stockholders' Equity
Net loss	(30,557)			(30,557)
Exercise of stock options (in shares)		77,336
Exercise of stock options	146		146
Stock-based compensation	1,976		1,976
Ending balance (in shares) at Jun. 30, 2021		33,825,620
Ending balance at Jun. 30, 2021	$ (122,394)		$ 205,823	$ (328,217)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities:
Net loss	$ (95,334)	$ (26,429)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization of property, equipment and finance lease right-of-use assets	1,999	1,395
Gain on disposal of property and equipment	0	(98)
Bad debt expense	377	0
Stock-based compensation	3,701	4,189
Change in equity-method investment	491	252
Change in fair value of debt instrument	45,661	2,222
Forgiveness of Paycheck Protection Program loan	(2,860)	0
Changes in operating assets and liabilities:
Accounts receivable	2,137	(1,382)
Other receivables	(5,013)	8,602
Prepaid expenses and other current assets	(5,769)	1,263
Other non-current assets	(1,733)	357
Trade payables	(130)	(4,347)
Accrued expenses	402	1,708
Other current and long-term liabilities	1,614	(838)
Net cash used in operating activities	(54,457)	(13,106)
Cash flows from investing activities:
Purchase of property and equipment	(2,822)	(650)
Payment for asset acquisition	(500)	0
Investment in equity method investee	0	(2,500)
Net cash used in investing activities	(3,322)	(3,150)
Cash flows from financing activities:
Proceeds from convertible loan notes	76,723	12,250
Principal payments on long-term debt	0	(1,952)
Proceeds from issuance of ordinary shares, net of issuance costs	0	1,961
Proceeds from Paycheck Protection Program loan	0	2,860
Proceeds from exercise of options	283	20
Proceeds from the exercise of warrants	233	7
Proceeds from issuance of warrants	263	0
Debt issuance costs incurred	(3,556)	0
Principal payments on finance lease	0	(1,231)
Net cash provided by financing activities	73,946	13,915
Net increase (decrease) in cash and cash equivalents	16,167	(2,341)
Cash and cash equivalents:
Beginning of period	19,228	20,904
End of period	$ 35,395	$ 18,563

Description of Business and Sig

Description of Business and Significant Accounting Policies	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Significant Accounting Policies	Organization and Background Rockley Photonics Holdings Limited (“Holdco”, "we", "us", or "our" ) was incorporated in the Cayman Islands with limited liability on March 11, 2021. As more fully described below, on August 11, 2021, Holdco completed a merger with SC Health Corporation and Rockley Photonics Limited ("Rockley"), with Rockley surviving the merger as a wholly-owned subsidiary of Holdco (the “Business Combination”). Immediately following the completion of the Business Combination and the related organizational transactions on August 11, 2021, Holdco received $168.0 million in gross proceeds. Rockley will operate, conduct and control all of the business and affairs of Holdco. SC Health and the shareholders of Rockley hold approximately 1.4% and 82.4% ownership interest in Rockley Photonics Holdings Limited, respectively. Basis of Presentation Our balance sheets have been prepared in accordance with generally accepted accounting principles in the United States ("GAAP"). Statements of income, shareholders’ equity and cash flows have not been presented because, as of March 11, 2021 and through to June 30, 2021, we have not engaged in any business or other activities except in connection with our formation. Description of Business Rockley Photonics Limited and its subsidiary entities (together, “we”, “us”, “our”, "Rockley" or, “the Company”) was founded in 2013 in the United Kingdom. We specialize in the research and development of integrated silicon photonics chipsets and have developed a versatile, application specific, third-generation silicon photonics platform specifically designed for the o ptical integration challenges facing numerous mega-trend markets. We have partnered with multiple tier-1 customers across the markets to deliver complex optical systems required for transformational sensor, communications, and medical product realization. Basis of Presentation and Preparation The accompanying unaudited condensed consolidated financial statements have been prepared by the Company, and reflect all adjustments, consisting only of normal recurring adjustments, that are, in the opinion of management, necessary for the fair presentation of our financial position, results of operations, comprehensive income, cash flows and shareholders’ equity for the interim periods presented. The statements have been prepared in accordance with GAAP for interim financial information. Accordingly, these statements do not include all information and footnotes required by GAAP for annual consolidated financial statements, and should be read in conjunction with our audited consolidated financial statements and notes thereto in the Company's audited consolidated financial statements as of and for the year ended December 31, 2020 included in the Rockley Photonics Holdings Limited 's Registration Statement on Form S-4 (File No. 333-255019), which was declared effective by the SEC on July 22, 2021. The results of operations for the three and six months ended June 30, 2021 are not necessarily indicative of the operating results to be expected for the full fiscal year or future operating periods. The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Such estimates include, but are not limited to, revenue recognition, reserves and allowances; valuation of intangibles; product warranties; employee compensation and benefit accruals; stock-based compensation; loss contingencies; income taxes and fair value measurements. Actual results could differ materially from those estimates. Management’s estimates include, as applicable, the anticipated impacts of the COVID-19 pandemic. Going Concern The Company has incurred net losses since inception, has an accumulated deficit of $328.2 million as of June 30, 2021 and negative cash flow from operations of $54.5 million for the six months ended June 30, 2021 and expects to incur losses from operations for the foreseeable future. As of June 30, 2021, the Company had cash and cash equivalents of approximately $35.4 million. The Company’s ability to meet its obligations in the ordinary course of business is dependent on its ability to obtain additional financing. As a result, there is substantial doubt about our ability to continue as a going concern. The condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business. The condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. Our future liquidity needs, and ability to address those needs, will largely be determined by our ability to obtain additional financing on terms acceptable to us. We will continue to seek additional capital through the sale of debt or equity, or other arrangements, however, there can be no assurance that we will be able to raise additional capital when needed or under acceptable terms, if at all. The sale of additional equity may dilute existing shareholders and newly issued shares may contain senior rights and preferences compared to currently outstanding ordinary shares. Issued debt securities may contain covenants and limit our ability to pay dividends or make other distributions to shareholders. If we are unable to obtain additional financing, operations may be scaled back or discontinued. Global Pandemic The COVID-19 global pandemic has prompted extraordinary measures by governments and businesses to control the spread of COVID-19 in most or all regions throughout the world. These actions have included travel bans, quarantines, and similar mandates for individuals to substantially restrict normal activities and for businesses to curtail normal operations. The COVID – 19 pandemic has adversely impacted our operational efficiency and caused delays in operational activities. During the second quarter of 2021, we continue to take cautious steps to protect our workforce, support community efforts, and follow local government guidelines. Certain key laboratory employees and facilities have continued internal testing and laboratory work to the extent necessary to service customer commitments. The remaining non-essential workforce were recommended to continue performing their duties from home. The ongoing impact will depend on the duration of the pandemic which is being mitigated by the vaccination of the general population and gradual easing of restrictions. Recently Adopted Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (“Topic 820”): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement , which modifies the disclosure requirements on fair value measurements in Topic 820, based on the concepts in the Concepts Statement, including the consideration of costs and benefits. An entity is permitted to early adopt either the entire standard or only the provisions that eliminate or modify requirements. The Company adopted this guidance on January 1, 2020. The adoption of the guidance did not have a material impact on the condensed consolidated financial statements. On June 16, 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments ("Topic 326"), requiring the measurement and recognition of expected credit losses for financial assets held at amortized cost, which include our accounts receivable and contract assets. The standard also requires that the Company recognizes credit impairment losses related to our available-for-sale debt securities through an allowance for credit losses instead of a reduction in the cost basis. The Company adopted this guidance on January 1, 2021. The adoption of the guidance did not have a material impact on the condensed consolidated financial statements. In August 2020, the FASB issued ASU 2020-06, Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity . This ASU simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts in an entity’s own equity. The Company adopted this guidance on January 1, 2021. The adoption of the guidance did not have a material impact on the condensed consolidated financial statements. Accounting Pronouncements Issued but Not Yet Adopted In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which affects general principles within Topic 740, and are meant to simplify and reduce the cost of accounting for income taxes. It removes certain exceptions to the general principles in Topic 740 and simplifies areas including franchise taxes that are partially based on income, transactions with a government that result in a step up in the tax basis of goodwill, the incremental approach for intraperiod tax allocation, interim period income tax accounting for year-to-date losses that exceed anticipated losses and enacted changes in tax laws in interim periods. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. The Company is currently evaluating the impact this guidance will have on the condensed consolidated financial statements.

Revenue Recognition

Revenue Recognition	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition Disaggregation of Revenue The following table depicts the disaggregation of revenue by geography, consistent with how we evaluate its financial performance (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) United States $ 2,195 $ 5,423 $ 3,966 $ 12,086 Rest of World $ — $ 2,458 $ — $ 2,458 Total revenue $ 2,195 $ 7,881 $ 3,966 $ 14,544 Significant Customers The following tables summarize our significant customers as of June 30, 2021 and December 31, 2020 and for the three and six months ended June 30, 2021 and 2020: Revenue Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) Customer A 100 % 69 % 100 % 83 % Customer B — % 31 % — % 17 % Accounts Receivable As of June 30, 2021 December 31, 2020 (Unaudited) Customer A 81 % 33 % Customer B 17 % 67 %

Equity Method Investment

Equity Method Investment	6 Months Ended
	Jun. 30, 2021
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investment As of June 30, 2021 and December 31, 2020, we held an investment in Hengtong Rockley Technology Co., Ltd (“HRT”) and we appointed two of the HRT's five board members. HRT manufactures and sells optical fiber transceivers based on silicon photonics chipsets. HRT has share capital consisting solely of ordinary shares. We hold 24.9% of HRT’s ordinary shares, which is the same as the proportion of its voting rights. We consider HRT to be a variable interest entity upon which the Company does exercise significant influence, but the Company concluded it does not control the investment. Accordingly, the investment in HRT is accounted for under the equity method. We elected to use a three-month lag to record our share of HRT’s results. See Note 11 , Related Party Transactions for details on the Company’s transactions with HRT. The following table summarizes our investment in HRT for the six months ended June 30, 2021 (in thousands): June 30, 2021 (Unaudited) Beginning balance $ 5,202 Investment in HRT — Remeasurement gain on HRT 269 Share of loss of HRT (760) Ending balance $ 4,711 Our maximum exposure to loss as a result of our involvement with HRT is limited to the balance of our investment.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Our financial assets are considered Level 1 in the fair value hierarchy and measured at fair value, were as follows (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Assets Cash equivalents: Money market funds $ 11,316 $ 11,516 All of our financial liabilities are considered Level 3 in the fair value hierarchy, where inputs to the valuation techniques used to measure fair value were considered unobservable. The Company’s assessment of the significance of a particular input to the fair value measurement in its entirety requires management to make judgements and consider factors specific to the liability. The financial liabilities subject to fair value measurement on a recurring basis, were as follows (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Financial Liabilities 3.00% – 2020 Convertible Notes $ 36,214 $ 32,106 8.00% – 2020 Convertible Notes 17,038 14,789 2020 Term Facility Loan 39,970 25,049 5.00% – $50.0 Million Convertible Notes 11,220 — 5.00% – $25.0 Million Convertible Notes 43,070 — 5.00% – $30.0 Million Convertible Notes 46,816 — Total financial liabilities $ 194,328 $ 71,944 Changes in the fair value of debt that is accounted for at fair value are presented as gains or losses in the condensed consolidated statements of operations and comprehensive loss under Change in Fair Value of Debt Instruments. 3.00% – 2020 Convertible Notes On March 9, 2020, we issued $21.3 million of 3.00% Convertible Notes and elected the fair value option of accounting for this debt instrument (see Note 6 , Long Term Debt for details). At June 30, 2021, the contractual outstanding principal of the 3.00% Convertible Notes Due 2025 was $21.3 million and the fair value was $36.2 million. As of June 30, 2021, we measured fair value using a binomial lattice model (which is discussed in further detail below) with the following significant inputs: Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 48.45 % Conversion price discount 25 % We recorded a loss of $1.1 million and $4.1 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of the 3.00% Convertible Notes, as follows (in thousands): Fair value at December 31, 2020 $ 32,106 Plus: Loss from change in fair value $ 4,108 Fair value at June 30, 2021 $ 36,214 A binomial lattice model was used to determine the fair value of the 3.00% Convertible Notes Due 2025 based on assumptions as to when these would be converted or redeemed at each decision point. Within the lattice model, the following assumptions were made: (i) upon IPO/Sale/Merger/SPAC or maturity, the convertible notes may be converted to ordinary shares or redeemed at principal and accrued interest; and (ii) upon qualified financing event, the convertible notes will automatically convert to ordinary shares. The lattice model uses the stock price, conversion price, maturity date, risk-free rate, estimated stock volatility and estimated credit spread. We remeasure the fair value of the debt instrument and record a change as a gain or loss in the statements of operations and comprehensive loss for each reporting period. 8.00% – 2020 Convertible Notes On February 19, 2020, we issued $8.0 million of 8.00% Convertible Notes and elected the fair value option of accounting for this debt instrument (see Note 6 , Long Term Debt for details). At June 30, 2021, the contractual outstanding principal of the 8.00% Convertible Notes Due 2027 was $8.0 million and the fair value was $17.0 million (including embedded warrants). As of June 30, 2021, we measured fair value using a binomial lattice model (which is discussed in further detail below) with the following significant inputs: Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 35 % Conversion price discount 40 % We recorded a loss of $0.5 million and $2.2 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of the 8.0% Convertible Notes, as follows (in thousands): Fair value at December 31, 2020 $ 14,789 Plus: Loss from change in fair value $ 2,249 Fair value at June 30, 2021 $ 17,038 A binomial lattice model was used to determine the fair value of the 8.00% Convertible Notes Due 2025 based on assumptions as to when these would be converted or redeemed at each decision point. Within the lattice model, the following assumptions were made: (i) upon IPO/Sale/Merger/SPAC or maturity, the convertible notes may be converted to ordinary shares or put at 125% of principal and accrued interest; and (ii) upon financing event, the convertible notes may be converted to ordinary shares. We remeasure the fair value of the debt instrument and record a change as a gain or loss from in the statements of operations and comprehensive loss for each reporting period. We issued liability classified warrants in conjunction with the issuance of the 8.00% Convertible Notes. The fair value of these warrants is embedded within the fair value of the 8.00% Convertible Notes presented in the table above. 2020 Term Facility Loan On September 29, 2020, we issued $35.0 million of convertible notes and elected the fair value option of accounting for this debt instrument (see Note 6 , Long Term Debt for details). At June 30, 2021, the contractual outstanding principal of the 2020 Term Facility Loan was $33.9 million and the fair value was $40.0 million. As of June 30, 2021, we measured fair value using a binomial lattice model and discounted cash flow approach for various exit event scenario, with the following significant inputs: Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 35 % We recorded a loss of $1.2 million and $14.9 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of 2020 Term Facility Loan, as follows (in thousands): Fair value at December 31, 2020 $ 25,049 Plus: Loss from change in fair value $ 14,921 Fair value at June 30, 2021 $ 39,970 A binomial lattice model was used to determine the fair value of the 2020 Term Facility Loan based on assumptions as to when these would be converted upon IPO/Sale/Merger/SPAC. Upon such event, the convertible notes will be paid off as following: (i) if par value exit, repayment of base multiple times principal plus unpaid interest; (ii) if greater value exit, repayment of base multiple plus add-on multiple ratio times principal plus unpaid interest. 5.00% – $50.0 Million Convertible Notes On January 11, 2021, we issued $50.0 million of 5.00% – $50.0 Million Convertible Notes and elected the fair value option of accounting for this debt instrument (see Note 6 , Long Term Debt for details). At June 30, 2021, the contractual outstanding principal of the 5.00% – $50.0 Million Convertible Notes Due 2026 was $10.3 million and the fair value was $11.2 million. As of June 30, 2021, we measured fair value using a binomial lattice model (which is discussed in further detail below) with the following significant inputs: Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 48.4 % We recorded a loss of $0.3 million and $0.9 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of 5.00%– $50.0 Million Convertible Note, as follows (in thousands): Fair value at January 11, 2021 $ 10,274 Plus: Loss from change in fair value $ 946 Fair value at June 30, 2021 $ 11,220 A binomial lattice model was used to determine the fair value of the 5.00% – $50.0 Million Convertible Notes Due 2026 based on assumptions as to when these would be converted or redeemed at each decision point. Within the lattice model, the following assumptions are made: (i) upon IPO/Sale/Merger/SPAC, the convertible notes may be converted to ordinary shares or put at principal and accrued interest; and (ii) upon qualified financing event or maturity, the convertible notes will automatically convert to ordinary shares at base price. The lattice model uses the stock price, conversion price, maturity date, risk-free rate, estimated stock volatility and estimated credit spread. We remeasure the fair value of the debt instrument and record the change as a gain or loss from a change as a gain or loss in the statements of operations and comprehensive loss for each reporting period. 5.00% – $25.0 Million Convertible Notes On December 31, 2020, we issued $25.0 million of 5.00% – $25.0 Million Convertible Notes and elected the fair value option of accounting for this debt instrument (see Note 6 , Long Term Debt for details). At June 30, 2021, the contractual outstanding principal of the 5.00% – $25.0 Million Convertible Notes Due 2025 was $25.0 million and the fair value was $43.1 million (including embedded warrants). As of June 30, 2021, we measured fair value using a binomial lattice model (which is discussed in further detail below) with the following significant inputs: Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 48.4 % We recorded a loss of $1.3 million and $5.5 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with subsequent fair value remeasurement of the 5.00% – $25.0 Million Convertible Notes, as follows (in thousands): Fair value at December 31, 2020 $ 37,592 Plus: Loss from change in fair value $ 5,478 Fair value at June 30, 2021 $ 43,070 A binomial lattice model was used to determine the fair value of the 5.00% – $25.0 Million Convertible Notes Due 2025 based on assumptions as to when these would be converted or redeemed at each decision point. Within the lattice model, the following assumptions were made: (i) upon SPAC, the convertible notes may be converted to ordinary shares or put at principal and accrued interest; (ii) upon qualified financing event, the convertible notes may be converted to ordinary shares with discount any time after financing date; and (iii) upon maturity, the convertible notes may converted to ordinary shares at $675.0 million divided by the number of fully diluted shares. We remeasure the fair value of the debt instrument and record a change as a gain or loss in the statements of operations and comprehensive loss for each reporting period. We issued liability classified warrants in conjunction with the issuance of the 5.00% – $25.0 Million Convertible Notes. We evaluated the terms of these warrants and noted that under ASC 480, our potential obligation to settle the warrants only when the exercise of contingencies is met. Due to this provision, ASC 480 requires that the warrants are classified as liabilities and combined within the 5.00% – $25.0 Million Convertible Notes. The fair value of these warrants is embedded within the fair value of the 5.00% – $25.0 Million Convertible Notes presented in the table above. 5.00% – $30.0 Million Convertible Notes On January 11, 2021, we issued $30.0 million of 5.00% Convertible Notes and elected the fair value option of accounting for this debt instrument (see Note 6 , Long Term Debt for details). At June 30, 2021, the contractual outstanding principal of the 5.00% – $30.0 Million Convertible Notes Due 2026 was $30.0 million and the fair value was $46.8 million. As of June 30, 2021 we measured fair value using a binomial lattice model (which is discussed in further detail below) with the following significant inputs: Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 48.4 % We recorded a loss of $1.4 million and $8.4 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of the 5.00% – $30.0 Million Convertible Notes, as follows (in thousands): Fair value at January 11, 2021 $ 38,403 Plus: Loss from change in fair value $ 8,413 Fair value at June 30, 2021 $ 46,816 A binomial lattice model was used to determine the fair value of the 5.00% Convertible Notes Due 2026 based on assumptions as to when these would be converted or redeemed at each decision point. Within the lattice model, the following assumptions were made: (i) upon SPAC, the convertible notes may be converted to ordinary shares or put at principal and accrued interest; and (ii) upon qualified financing event or maturity, the convertible notes will automatically convert to ordinary shares at base price. The lattice model uses the stock price, conversion price, maturity date, risk-free rate, estimated stock volatility and estimated credit spread. We remeasure the fair value of the debt instrument and record a change as a gain or loss in the statements of operations and comprehensive loss for each reporting period.

Balance Sheet Components

Balance Sheet Components	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	Balance Sheet Components Cash and cash equivalents Cash and cash equivalents balances were concentrated by location as follows: As of June 30, 2021 December 31, 2020 (Unaudited) United Kingdom 92 % 96 % United States 7 % 3 % Other 1 % 1 % Other receivables (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) R&D tax credit receivable $ 21,911 $ 17,412 Grants receivable 573 — VAT receivable 549 607 Other receivable 4 5 Total other receivables $ 23,037 $ 18,024 Property and equipment, net (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Computer equipment $ 1,744 $ 1,218 Lab equipment 10,081 7,607 Motor vehicles 31 31 Furniture and fixtures 265 265 Leasehold improvements 704 704 Assets under construction 561 27 Total property and equipment $ 13,386 $ 9,852 Less: accumulated depreciation (7,162) (5,802) Total property and equipment, net $ 6,224 $ 4,050 Total depreciation expense for the three months ended June 30, 2021 and 2020 was $1.0 million and $0.6 million, respectively. Total depreciation expense for the six months ended June 30, 2021 and 2020 was $1.8 million and $1.2 million, respectively. Finance lease right-of-use assets, net (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Finance lease right-of-use assets $ 2,966 $ 2,966 Less: accumulated amortization (1,020) (834) Total finance lease right-of-use assets, net $ 1,946 $ 2,132 Amortization expense for the three months ended June 30, 2021 and 2020 was $0.1 million and $0.1 million, respectively. Amortization expense for the six months ended June 30, 2021 and 2020 was $0.2 million and $0.2 million, respectively. Intangible assets, net (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) In-process research and development $ 3,048 $ 3,048 Total intangible assets, net $ 3,048 $ 3,048 The Company reviews its intangible assets for potential impairment whenever events or circumstances indicate that the carrying value of the intangible assets may not be recoverable. No impairment charges were recorded for the three and six months ended June 30, 2021 and 2020. Other non-current assets (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Capitalized transaction costs $ 8,496 $ 121 Operating right of use assets $ 3,219 $ 1,486 Total other non-current assets $ 11,715 $ 1,607 Capitalized transaction costs as of June 30, 2021 consist of capitalized professional fees related to accounting, legal and audit matters incurred by the Company, in connection with the Business Combination transaction. Accrued expenses (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Accrued bonus $ 2,926 $ 3,349 Accrued payroll and benefits 2,191 1,524 Accrued taxes 75 332 Accrued fabrication costs 2,304 2,321 Share appreciation rights 741 706 Other accrued expenses 3,867 2,163 Total accrued expenses $ 12,104 $ 10,395

Long Term Debt

Long Term Debt	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Long Term Debt	Long Term Debt The following table summarizes information relating to our long-term debt, (in thousands): June 30, 2021 (Unaudited) Principal Fair Value Net 3.00% – 2020 Convertible Notes $ 21,281 $ 14,933 $ 36,214 8.00% – 2020 Convertible Notes 8,000 9,038 17,038 2020 Term Facility Loan 33,949 6,021 39,970 5.00% – $50.0 Million Convertible Notes 10,274 946 11,220 5.00% – $25.0 Million Convertible Notes 25,000 18,070 43,070 5.00% – $30.0 Million Convertible Notes 30,000 16,816 46,816 Total long-term debt $ 128,504 $ 65,824 $ 194,328 Less: current portion of long-term debt — — — Long-term debt, net of current portion $ 128,504 $ 65,824 $ 194,328 December 31, 2020 Principal Fair Value Net 3.00% – 2020 Convertible Notes $ 21,281 $ 10,825 $ 32,106 8.00% – 2020 Convertible Notes 8,000 6,789 14,789 2020 Term Facility Loan 22,500 2,549 25,049 Paycheck Protection Program 2,860 — 2,860 Total long-term debt $ 54,641 $ 20,163 $ 74,804 Less: current portion of long-term debt — — — Long-term debt, net of current portion $ 54,641 $ 20,163 $ 74,804 Future minimum payments under the debt agreements as of June 30, 2021 are as follows (in thousands): Convertible 2021 (for the remaining period) $ — 2022 — 2023 — 2024 — 2025 114,179 Thereafter 50,274 Total future minimum payments $ 164,453 Less: current portion of debt principal — Non-current portion of debt principal $ 164,453 3.00% – 2020 Convertible Notes The discussion on the 3.00% – 2020 Convertible Notes is fully described in Note 7 of the “Notes to Consolidated Financial Statements” included in the Rockley Photonics Holdings Limited 's Registration Statement on Form S-4 (File No. 333-255019), filed with Securities and Exchange Commission (SEC) on May 28, 2021. We accrued unpaid interest of $0.1 million and $0.3 million in the three and six months ended June 30, 2021, respectively. The accrued unpaid interest for the three and six months ended June 30, 2020 was immaterial. For t he three and six months ended June 30, 2021, we recorded a loss of $1.1 million and $4.1 million, respectively in the condensed consolidated statements of operations and comprehensive loss under Change in Fair Value of Debt Instruments. See Note 4 , Fair Value Measurements for information about the assumptions used to measure the fair value of the 3.00% Convertible Notes as of June 30, 2021. 8.00% – 2020 Convertible Notes The discussion on the 8.00% Convertible Notes is fully described in Note 7 of the “Notes to Consolidated Financial Statements” included in the Rockley Photonics Holdings Limited 's Registration Statement on Form S-4 (File No. 333-255019), filed with Securities and Exchange Commission (SEC) on May 28, 2021. We accrued unpaid interest of $0.2 million and $0.3 million in the three and six months ended June 30, 2021, respectively. We accrued unpaid interest of $0.1 million and $0.2 million f or the three and six months ended June 30, 2020, respectively. For the three and six months ended June 30, 2021, we recorded a loss of $0.5 million and $2.2 million, respectively in the condensed consolidated statements of operations and comprehensive loss under Change in Fair Value of Debt Instruments. See Note 4 , Fair Value Measurements for information about the assumptions used to measure the fair value of 8.00% Convertible Notes as of June 30, 2021. 2020 Term Facility Loan The discussion on the 2020 Term Facility Loan is fully described in Note 7 of the “Notes to Consolidated Financial Statements” included in the Rockley Photonics Holdings Limited 's Registration Statement on Form S-4 (File No. 333-255019), filed with Securities and Exchange Commission (SEC) on May 28, 2021. The Company paid interest of $0.2 million and $0.3 million in the three and six months ended June 30, 2021, respectively. As of June 30, 2021, the total amount borrowed was $33.9 million. For the three and six months ended June 30, 2021, we recorded a loss of $1.2 million and $14.9 million, respectively in the condensed consolidated statements of operations and comprehensive loss under Change in Fair Value of Debt Instruments. See Note 4 , Fair Value Measurements for information about the assumptions used to measure the fair value of 2020 Term Facility Loan as of June 30, 2021. On May 25, 2021, we entered into an amendment to the 2020 Term Facility Loan which modified the payment and maturity terms such that 30% of the outstanding principal was converted to ordinary shares of Rockley Photonics Holdings Limited at the closing of a business combination and merger with a SPAC and the remaining 70% will be repaid on or before August 31, 2022. 5.00% – $50.0 Million Convertible Notes On January 11, 2021, we issued convertible loan notes for an aggregate principal amount of $50.0 million. The 5.00% – $50.0 Million Convertible Notes mature on the fifth anniversary date of the instrument and bear interest at a rate of 5.00% per annum. The 5.00% – $50.0 Million Convertible Notes contain no financial covenants. We accrued unpaid interest of $0.1 million and $0.3 million in the three and six months ended June 30, 2021, respectively. As of June 30, 2021, the total amount borrowed was $10.3 million. The 5.00% – $50.0 Million Convertible Notes are convertible as follows: (a) In the event of a qualified financing even with total proceeds raised not less than $25.0 million, the outstanding principal amount and any unpaid accrued interest shall automatically convert into the most senior class of share at a conversion price being lower of 15% discount to the per share subscription price of the equity shares or the price obtained by diving $1,500.0 million by fully diluted share capital of the Company at the date of conversion; (b) At an exit event, redeem the outstanding principal amount and any unpaid accrued interest on the original principal or convert the outstanding principal amount of all notes and any unpaid accrued interest into the most senior class of share of the Company at a conversion price equal to the lower of 15% discount to the price per share and the price obtained by dividing $1,500.0 million by fully diluted share capital of the Company at the date of conversion; (c) At the maturity date, convert into the most senior class of shares at a conversion price by dividing $1,500.0 million by fully diluted share capital of the Company at the date of conversion. We elected to account for the 5.00% – $50.0 Million Convertible Notes at fair value as of the issuance date. Management believes that the fair value option better reflects the underlying economics of the 5.00% – $50.0 Million Convertible Notes. Under the fair value election, changes in fair value are reported in the condensed consolidated statements of operations and comprehensive loss under Change in Fair Value of Debt Instruments. For the three and six months ended June 30, 2021, we recorded a loss of $0.3 million and $0.9 million, respectively. See Note 4 , Fair Value Measurements for information about the assumptions we used to measure the fair value of the 5.00% – $50.0 Million Convertible Notes. 5.00% – $25.0 Million Convertible Notes On December 31, 2020, we issued convertible loan notes in an aggregate principal amount of $25.0 million. The 5.00% – $25.0 Million Convertible Notes mature on the fifth anniversary date of the instrument and bear interest at a rate of 5.0% per annum. The 5.00% – $25.0 Million Convertible Notes contain no financial covenants. We accrued unpaid interest of $0.3 million and $0.6 million in the three and six months ended June 30, 2021. The 5.00% – $25.0 Million Convertible Notes were convertible as follows: (a) In an equity qualified financing event with total proceeds raised not less than $25.0 million, the outstanding principal amount and any unpaid accrued interest shall automatically convert into the most senior class of share at a conversion price being lower of 25% discount to the per share subscription price of the equity shares or the price obtained by diving $800.0 million by fully diluted share capital of the Company at the date of conversion; (b) At an exit event, redeem the outstanding notes for an amount equal to 100% of the outstanding principal plus accrued interest or convert the outstanding principal amount into the most senior class of share of the Company, at a conversion price equal to the lower of 25% discount to the price per share and the price obtained by dividing $800.0 million by fully diluted share capital of the Company at the date of conversion; or (c) At the maturity date, convert into the most senior class of shares at a conversion price by dividing $675.0 million by the number of issued shares in the capital of the Company on a fully diluted basis or repay the amount equal to 100% of the outstanding principal amount plus any accrued interest. We elected to account for the 5.00% – $25.0 Million Convertible Notes at fair value as of the issuance date. Management believes that the fair value option better reflects the underlying economics of the 5.00% – $25.0 Million Convertible Notes. Under the fair value election, changes in fair value are reported in the condensed consolidated statements of operations and comprehensive loss under Change in Fair Value of Debt Instruments. For the three and six months ended June 30, 2021, we recorded a loss of $1.3 million and $5.5 million, respectively. See Note 4 , Fair Value Measurements for information about the assumptions we used to measure the fair value of 5.00% – $25.0 Million Convertible Notes. In conjunction with the 5.00% – $25.0 Million Convertible Notes, we also issued the holder 278,775 warrants (“5.0% Investor Warrants”) which are convertible into ordinary shares of the Company. The warrants have an exercise price of $0.00001 per share and will only become exercisable upon the specified conversion event. The number of shares that the warrants will convert into varies depending on the type of conversion event. The value of the warrants is embedded within the 5.00% – $25.0 Million Convertible Notes. 5.00% – $30.0 Million Convertible Notes On January 11, 2021, we issued convertible loan notes in an aggregate principal amount of $30.0 million (the “5.00% – $30.0 Million Convertible Notes”). The 5.00% – $30.0 Million Convertible Notes mature on the fifth anniversary date of the instrument and bear interest at a rate of 5.0% per annum. The 5.00% – $30.0 Million Convertible Notes contain no financial covenants. We accrued unpaid interest of $0.4 million and $0.7 million in the three and six months ended June 30, 2021, respectively. The 5.00% – $30.0 Million Convertible Notes were convertible as follows: (a) In an equity qualified financing event with total proceeds raised not less than $25.0 million, the outstanding principal amount and any unpaid accrued interest shall automatically convert into the most senior class of share at a conversion price being lower of 25% discount to the per share subscription price of the equity shares or the price obtained by diving $800.0 million by fully diluted share capital of the Company at the date of conversion; (b) At an exit event, redeem the outstanding notes for an amount equal to the outstanding principal plus any unpaid accrued interest or convert the outstanding principal amount of all notes and any unpaid accrued interest into the most senior class of share of the Company, at a conversion price equal to the lower of a 25% discount to the price per share and the price obtained by dividing $800.0 million by fully diluted share capital of the Company at the date of conversion; or (c) At the maturity date, convert into the most senior class of shares at a conversion price by dividing $800.0 million by fully diluted share capital of the Company at the date of conversion. We elected to account for the 5.00% – $30.0 Million Convertible Notes at fair value as of the issuance date. Management believes that the fair value option better reflects the underlying economics of the 5.00% – $30.0 Million Convertible Notes. Under the fair value election, changes in fair value are reported in the condensed consolidated statements of operations and comprehensive loss under Change in Fair Value of Debt Instruments. For the three and six months ended June 30, 2021, we recorded a loss of $1.4 million and $8.4 million, respective. See Note 4 , Fair Value Measurements for information about the assumptions we used to measure the fair value of the 5.00%– $30.0 Million Convertible Notes. Paycheck Protection Program The discussion on paycheck protection program is fully described in Note 7 of the “Notes to Consolidated Financial Statements” included in the Rockley Photonics Holdings Limited 's Registration Statement on Form S-4 (File No. 333-255019), filed with Securities and Exchange Commission (SEC) on May 28, 2021. During June 2021, the $2.9 million of borrowings outstanding under the Paycheck Protection Program ("PPP") Loan was forgiven in full. Forgiveness income is recorded as a component of other income, net in the condensed consolidated statements of operations and comprehensive loss.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2021
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesIncome tax expense was $0.1 million in both the three months ended June 30, 2021 and 2020. Income tax expense was $0.2 million in both the six months ended June 30, 2021 and 2020. The effective income tax rate was less than 1.0% in the three and six months ended June 30, 2021 and 2020. Our effective tax rate differs from the U.K. statutory rate primarily due to a substantially full valuation allowance against our net deferred tax assets where it is more likely than not that some or all of the deferred tax assets will not be realized. The income tax expense is primarily related to corporate income taxes in the United States, which operates on a cost–plus arrangements and minimum filing fees in the foreign jurisdictions where we have operations.

Ordinary Shares

Ordinary Shares	6 Months Ended
	Jun. 30, 2021
Equity [Abstract]
Ordinary Shares	Shareholder's EquityOn March 11, 2021, upon formation of Holdco, our board of directors (the "Rockley Photonics Holdings Limited Board") authorized the issuance of 1 ordinary share with an initial par value of $0.00001 per share, to Dr. Andrew Rickman, OBE. Rockley contributed additional paid-in capital of $50,000 at the formation of Holdco in contemplation of the organizational transactions discussed in sections below.Ordinary SharesOrdinary shares have no liquidation preferences and entitle holders to one vote per share. Ordinary shareholders are entitled to receive non-cumulative dividends, when and if declared by our Board of Directors.

Earnings per Share

Earnings per Share	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Earnings Per Share	Earnings per Share The following is a calculation of basic and diluted net loss per share (in thousands, except for share and per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) Basic and diluted: Net loss $ (30,557) $ (10,003) $ (95,334) $ (26,429) Weighted average ordinary shares 33,922,973 33,625,899 33,850,070 33,554,441 Basic and diluted net loss per share $ (0.90) $ (0.30) $ (2.82) $ (0.79) Basic net loss per share is calculated by dividing net loss for the period by the weighted average number of the ordinary shares outstanding plus 108,821 and 132,099 outstanding warrants for the three months ended June 30, 2021 and 2020 with a $0.01 exercise price. For the three and six months ended June 30, 2021 and 2020, we excluded the potential effect of the following in the calculation of the diluted loss per share, as the effect would be anti-dilutive due to losses incurred: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) Outstanding warrants, less outstanding warrants with a $0.01 exercise price 899,698 842,717 899,698 842,717 Outstanding options (including performance options) 6,700,277 6,412,668 6,700,277 6,412,668 7,599,975 7,255,385 7,599,975 7,255,385

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Company has established a number of share-based incentive plans for current employees, directors and others, which include Share Appreciation Rights ("SARs"), 2013 Share Option Plan and Warrants. Share Appreciation Rights As of June 30, 2021 and December 31, 2020, the Company had recorded liabilities of $0.7 million and $0.7 million related to these SARs based on their fair value of $24.70 and $20.28 per share as of June 30, 2021 and December 31, 2020, respectively. The total expense that we recognized for the SARs in the condensed consolidated statements of operations and comprehensive loss under selling, general and administrative wa s immaterial for the three and six months ended June 30, 2021 and 2020, respectively. 2013 Share Option Plan As of June 30, 2021, t here were 11,458,989 shares authorized for issuance under the Plan, of which 3,088,276 shares were available for grant. The following table summarizes the stock option activity related to the 2013 Share Option Plan : Number of Average Remaining Intrinsic (In thousands) Balances as of December 31, 2020 7,207,044 $ 4.94 6.75 $ 110,552 Options granted — $ — Options exercised (164,580) $ 1.72 Options forfeited (331,068) $ 10.30 Options expired (11,119) $ 6.66 Balances as of June 30, 2021 6,700,277 $ 4.75 6.16 $ 133,661 Options exercisable—June 30, 2021 4,989,774 $ 3.56 5.31 $ 105,483 The aggregated intrinsic value represents the difference between the exercise price and the fair value of ordinary shares . Th e weighted-average grant-date fair value of options granted during the six months ended June 30, 2021 was nil since no options were granted during the period. Stock-based compensation expense for all equity arrangements is included in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 ( Unaudited) ( Unaudited) Cost of revenue $ 363 $ 870 $ 631 $ 1,341 Research and development 1,171 1,330 2,219 2,081 Selling, general and administrative 442 345 851 767 Total stock-based compensation expense $ 1,976 $ 2,545 $ 3,701 $ 4,189 As of June 30, 2021, total unrecognized compensation expense related to unvested options granted to employees under the Company’s stock option plan was $11.9 million, which is expected to be recognized over a weighted average period o f 1.2 years . Performance Options For the three months ended June 30, 2021 and 2020, we recognized a total expense of $0.1 million and $0.02 million in relation to the performance-based options. For the six months ended June 30, 2021 and 2020, we recognized a total expense of $0.2 million and $0.1 million. As of June 30, 2021 and December 31, 2020, there were approximately $1.0 million and $1.2 million of unrecognized stock-based compensation expense related to the performance-based options. During the six months ended June 30, 2021, no additional performance-based options were granted. Warrants The following table summarizes information related to our outstanding warrants. Investor Warrants in connection with the 8.00% – 2020 Convertible Notes and 5.00% – $25.0 Million Convertible Notes were excluded from the below table as they are classified as liabilities. Number of Weighted- Weighted- Balances as of December 31, 2020 1,013,103 $ 7.33 6.45 Warrants issued 18,694 $ 18.16 Warrants exercised (23,278) $ 0.00 Balances as of June 30, 2021 1,008,519 $ 7.70 5.78

Related Party Transactions

Related Party Transactions	6 Months Ended
	Jun. 30, 2021
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions The Company formed HRT, a joint venture with Hengtong Optic-Electric Co., Ltd. in 2017, which was recognized by the Company as an equity method investment. During the three and six months ended June 30, 2021, we mad e no sales to HRT. During the three and six months ended June 30, 2020, we mad e sales to HRT of $2.5 million. As of June 30, 2021 and December 31, 2020, the balance owed by the joint venture amounted to $0.4 million and $3.3 million, respectively, and is included in accounts receivable in the accompanying balance sheets. As of June 30, 2021, there was no balance owed to the joint venture. The Company engages two affi liate entities of the Company’s directors for consulting and administrative services. The fees incurred for these services were immaterial for the three and six months ended June 30, 2021 and 2020. As of June 30, 2020 and December 31, 2020, the amounts included in accounts payable and accrued expenses in the accompanying condensed consolidated balance sheets were not considered material.

Leases

Leases	6 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Leases	Leases The weighted average remaining lease term was 3 years for operating leases as of June 30, 2021. The weighted average discount rate was 6% for operating leases as of June 30, 2021. Finance lease costs were immaterial for the three and six months ended June 30, 2021 and 2020. The components of operating lease cost for the three and six months ended June 30, 2021 and 2020, were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) Operating Lease Cost: Fixed lease cost $ 292 213 $ 505 426 Variable lease cost 36 81 119 121 Total operating lease cost $ 328 $ 294 $ 624 $ 547 The supplemental cash flow information related to our operating leases is as follows (in thousands): Six Months Ended June 30, 2021 2020 Supplemental Cash Flow Information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 462 $ 454 Operating cash flows for finance leases $ — $ 12 Financing cash flows for finance leases $ — $ 933 Right-of-use assets obtained in exchange of lease obligations: Right-of-use assets obtained in exchange for new operating lease liabilities $ 2,187 $ — There are no finance lease liabilities as of June 30, 2021. Maturities of operating lease liabilities as of June 30, 2021, are as follows (in thousands): Operating Leases 2021 (for the remaining period) $ 582 2022 1,239 2023 931 2024 437 2025 327 Thereafter 394 Total lease obligation $ 3,910 Less: Imputed interest (408) Total lease liabilities $ 3,502 Less: Current lease liabilities (1,020) Total non-current lease liabilities $ 2,482
Leases	Leases The weighted average remaining lease term was 3 years for operating leases as of June 30, 2021. The weighted average discount rate was 6% for operating leases as of June 30, 2021. Finance lease costs were immaterial for the three and six months ended June 30, 2021 and 2020. The components of operating lease cost for the three and six months ended June 30, 2021 and 2020, were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) Operating Lease Cost: Fixed lease cost $ 292 213 $ 505 426 Variable lease cost 36 81 119 121 Total operating lease cost $ 328 $ 294 $ 624 $ 547 The supplemental cash flow information related to our operating leases is as follows (in thousands): Six Months Ended June 30, 2021 2020 Supplemental Cash Flow Information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 462 $ 454 Operating cash flows for finance leases $ — $ 12 Financing cash flows for finance leases $ — $ 933 Right-of-use assets obtained in exchange of lease obligations: Right-of-use assets obtained in exchange for new operating lease liabilities $ 2,187 $ — There are no finance lease liabilities as of June 30, 2021. Maturities of operating lease liabilities as of June 30, 2021, are as follows (in thousands): Operating Leases 2021 (for the remaining period) $ 582 2022 1,239 2023 931 2024 437 2025 327 Thereafter 394 Total lease obligation $ 3,910 Less: Imputed interest (408) Total lease liabilities $ 3,502 Less: Current lease liabilities (1,020) Total non-current lease liabilities $ 2,482

Commitment and Contingencies

Commitment and Contingencies	6 Months Ended
	Jun. 30, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Contingencies From time to time, we are a party to various lawsuits, claims and other legal proceedings that arise in the ordinary course of business. We apply accounting for contingencies to determine when and how much to accrue for and disclose related to legal and other contingencies. Accordingly, we disclose contingencies deemed to be reasonably possible and accrue loss contingencies when, in consultation with legal advisors, it is concluded that a loss is probable and reasonably estimable. Although the ultimate aggregate amount of monetary liability or financial impact with respect to these matters is subject to many uncertainties and is therefore not predictable with assurance, management believes that as of June 30, 2021 there are no litigations pending that could have, individually and in the aggregate, a material adverse effect on our financial position, results of operations or cash flows. Financial Commitments In the ordinary course of business, we make commitments to third-party suppliers for various research and development activities. As of June 30, 2021 and December 31, 2020, we had $8.1 million and $3.0 million, respectively, in contractual obligations for which we have not yet received the services.

Defined Contribution Plan

Defined Contribution Plan	6 Months Ended
	Jun. 30, 2021
Retirement Benefits [Abstract]
Defined Contribution Plan	Defined Contribution PlanWe have defined contribution plans, under which we contribute based on a percentage of the employees’ elected contributions. We will have no legal or constructive obligation to pay further amounts. Obligations for contributions to defined contribution plans are recognized within selling, general and administrative expenses and research and development in the condensed consolidated statements of operations and comprehensive loss. Defined contributions were $0.2 million and $0.1 million for the three months ended June 30, 2021 and 2020, respectively. Defined contributions were $0.4 million and $0.3 million for the six months ended June 30, 2021 and 2020, respectively.

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	6 Months Ended
	Jun. 30, 2021
Supplemental Cash Flow Elements [Abstract]
Supplemental Cash Flow Information	Supplemental Cash Flow InformationNon-cash operating, investing, and financing activities, and supplemental cash flow information are as follows (in thousands): Six Months Ended June 30, 2021 2020 (Unaudited) Supplemental Cash Flow Information: Interest paid $ 271 $ 45 Income tax paid $ 210 $ 80 Non-cash Operating Activities: Right-of-use assets obtained in exchange for new operating lease liabilities $ 2,187 $ — $ 2,187 0 Non-cash Investing Activities: Unpaid property and equipment received $ 1,163 $ 295 $ 1,163 $ 295 Non-cash Financing Activities: Unpaid deferred transaction costs $ 5,201 $ — Forgiveness of Paycheck Protection Program loan $ (2,860) $ — $ 2,341 $ —

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2021
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Subsequent events have been evaluated through the date that these financial statements were issued. In relation to the Business Combination, on July 22, 2021, Holdco’s Form S-4 Registration Statement received a Notice of Effectiveness from the SEC. On August 9, 2021, among other things, we proposed to the High Court of the United Kingdom a transfer scheme of arrangement under Part 26 of the Companies Act pursuant to which our shareholders exchanged all of Rockley Photonics Limited shares for Rockley Photonics Holdings Limited ordinary shares, at a conversion price of $10.00 per share. The transfer was conditional upon the approval of the Business Combination Agreement, the Business Combination and the Plan of Merger by SC Health shareholders. All items were approved on August 6, 2021. The Business Combination was consummated on August 11, 2021 and Holdco became a publicly traded company listed on the New York Stock Exchange ("NYSE") under the symbol "RKLY". Subsequent to the consummation of the Business Combination, Rockley and its subsidiary entities became a wholly owned subsidiary of Holdco. Subsequent events have been evaluated through the date that these financial statements were issued. Rockley Photonics Holdings Limited ("Holdco") was formed on March 11, 2021 for the purpose of effecting a merger or other similar business combination with one or more operating businesses. Holdco had neither engaged in any operations nor generated significant revenue through June 30, 2021. On March 19, 2021, the Company entered into a definitive agreement to combine with SC Health Corporation ("SC Health"), a publicly traded special purpose acquisition company. The transaction resulted in Rockley becoming a publicly traded company. On July 22, 2021, Rockley Photonics Holdings Limited's Form S-4 Registration Statement received a Notice of Effectiveness from the Securities and Exchange Commission ("SEC"). On August 9, 2021, among other things, we proposed to the High Court of the United Kingdom a transfer scheme of arrangement under Part 26 of the Companies Act pursuant to which our shareholders exchanged all of Rockley Photonics Limited shares for Rockley Photonics Holdings Limited ordinary shares, at a conversion price of $10.00 per share. The transfer is conditional upon the approval of the Business Combination Agreement, the Business Combination and the Plan of Merger by SC Health shareholders. The Business Combination was consummated on August 11, 2021 and Rockley Photonics Holdings Limited became a publicly traded company listed on the New York Stock Exchange ("NYSE") under the symbol "RKLY". S ubsequent to the consummation of the Business Combination, the Rockley Photonics Limited and its subsidiary entities became a wholly owned subsidiary of Rockley Photonics Holdings Limited. Immediately following the completion of the Business Combination and the related organizational transactions on August 11, 2021, the following took place: Rockley Photonics Holdings Limited received $126.9 million in proceeds, net of underwriting discounts and commissions. The shareholders of SC Health and Rockley Photonics Limited hold 12,339,650 and 103,916,607 shares, or approximately 9.8% and 82.3% ownership interest in Rockley Photonics Holdings Limited, respectively. The Company's issued and o utstanding convertible loan notes (other than certain convertible notes issued in connection with the 2020 Term Facility Loan, of which 30% were converted to ordinary shares of Holdco and 70% were converted to convertible notes of Holdco that mature on August 31, 2022), inclusive of interest accrued thereon, converted into ordinary shares of Holdco at a conversio n price of $10.00 per sh are. The Company's issued and outstanding warrants were converted to ordinary shares of Holdco. In connection with the transaction, we incurred legal, accounting, and other professional fees in connection with the completion of the Business Combination. Through August 12, 2021, we have paid approximately $29.3 million of these expenses. As of August 12, 2021, approximately $14.8 million of these expenses remained unpaid.

Description of Business and S_2

Description of Business and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Preparation	Basis of Presentation and Preparation The accompanying unaudited condensed consolidated financial statements have been prepared by the Company, and reflect all adjustments, consisting only of normal recurring adjustments, that are, in the opinion of management, necessary for the fair presentation of our financial position, results of operations, comprehensive income, cash flows and shareholders’ equity for the interim periods presented. The statements have been prepared in accordance with GAAP for interim financial information. Accordingly, these statements do not include all information and footnotes required by GAAP for annual consolidated financial statements, and should be read in conjunction with our audited consolidated financial statements and notes thereto in the Company's audited consolidated financial statements as of and for the year ended December 31, 2020 included in the Rockley Photonics Holdings Limited 's Registration Statement on Form S-4 (File No. 333-255019), which was declared effective by the SEC on July 22, 2021. The results of operations for the three and six months ended June 30, 2021 are not necessarily indicative of the operating results to be expected for the full fiscal year or future operating periods. The preparation of the condensed consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting periods. Such estimates include, but are not limited to, revenue recognition, reserves and allowances; valuation of intangibles; product warranties; employee compensation and benefit accruals; stock-based compensation; loss contingencies; income taxes and fair value measurements. Actual results could differ materially from those estimates. Management’s estimates include, as applicable, the anticipated impacts of the COVID-19 pandemic.
Going Concern	Going Concern The Company has incurred net losses since inception, has an accumulated deficit of $328.2 million as of June 30, 2021 and negative cash flow from operations of $54.5 million for the six months ended June 30, 2021 and expects to incur losses from operations for the foreseeable future. As of June 30, 2021, the Company had cash and cash equivalents of approximately $35.4 million. The Company’s ability to meet its obligations in the ordinary course of business is dependent on its ability to obtain additional financing. As a result, there is substantial doubt about our ability to continue as a going concern. The condensed consolidated financial statements have been prepared on a going concern basis, which contemplates the realization of assets and satisfaction of liabilities in the normal course of business. The condensed consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty. Our future liquidity needs, and ability to address those needs, will largely be determined by our ability to obtain additional financing on terms acceptable to us. We will continue to seek additional capital through the sale of debt or equity, or other arrangements, however, there can be no assurance that we will be able to raise additional capital when needed or under acceptable terms, if at all. The sale of additional equity may dilute existing shareholders and newly issued shares may contain senior rights and preferences compared to currently outstanding ordinary shares. Issued debt securities may contain covenants and limit our ability to pay dividends or make other distributions to shareholders. If we are unable to obtain additional financing, operations may be scaled back or discontinued.
Global Pandemic	Global Pandemic The COVID-19 global pandemic has prompted extraordinary measures by governments and businesses to control the spread of COVID-19 in most or all regions throughout the world. These actions have included travel bans, quarantines, and similar mandates for individuals to substantially restrict normal activities and for businesses to curtail normal operations. The COVID –
Recently Adopted Accounting Pronouncements and Accounting Pronouncements Issued but Not Yet Adopted	Recently Adopted Accounting Pronouncements In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (“Topic 820”): Disclosure Framework – Changes to the Disclosure Requirements for Fair Value Measurement , which modifies the disclosure requirements on fair value measurements in Topic 820, based on the concepts in the Concepts Statement, including the consideration of costs and benefits. An entity is permitted to early adopt either the entire standard or only the provisions that eliminate or modify requirements. The Company adopted this guidance on January 1, 2020. The adoption of the guidance did not have a material impact on the condensed consolidated financial statements. On June 16, 2016, the FASB issued ASU No. 2016-13, Measurement of Credit Losses on Financial Instruments ("Topic 326"), requiring the measurement and recognition of expected credit losses for financial assets held at amortized cost, which include our accounts receivable and contract assets. The standard also requires that the Company recognizes credit impairment losses related to our available-for-sale debt securities through an allowance for credit losses instead of a reduction in the cost basis. The Company adopted this guidance on January 1, 2021. The adoption of the guidance did not have a material impact on the condensed consolidated financial statements. In August 2020, the FASB issued ASU 2020-06, Debt-Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40): Accounting for Convertible Instruments and Contracts in an Entity’s Own Equity . This ASU simplifies the accounting for certain financial instruments with characteristics of liabilities and equity, including convertible instruments and contracts in an entity’s own equity. The Company adopted this guidance on January 1, 2021. The adoption of the guidance did not have a material impact on the condensed consolidated financial statements. Accounting Pronouncements Issued but Not Yet Adopted In December 2019, the FASB issued ASU 2019-12, Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes, which affects general principles within Topic 740, and are meant to simplify and reduce the cost of accounting for income taxes. It removes certain exceptions to the general principles in Topic 740 and simplifies areas including franchise taxes that are partially based on income, transactions with a government that result in a step up in the tax basis of goodwill, the incremental approach for intraperiod tax allocation, interim period income tax accounting for year-to-date losses that exceed anticipated losses and enacted changes in tax laws in interim periods. ASU 2019-12 is effective for fiscal years beginning after December 15, 2020, with early adoption permitted. The Company is currently evaluating the impact this guidance will have on the condensed consolidated financial statements.

Revenue Recognition (Tables)

Revenue Recognition (Tables)	6 Months Ended
	Jun. 30, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table depicts the disaggregation of revenue by geography, consistent with how we evaluate its financial performance (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) United States $ 2,195 $ 5,423 $ 3,966 $ 12,086 Rest of World $ — $ 2,458 $ — $ 2,458 Total revenue $ 2,195 $ 7,881 $ 3,966 $ 14,544
Schedules of Concentration of Risk, by Customer	The following tables summarize our significant customers as of June 30, 2021 and December 31, 2020 and for the three and six months ended June 30, 2021 and 2020: Revenue Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) Customer A 100 % 69 % 100 % 83 % Customer B — % 31 % — % 17 % Accounts Receivable As of June 30, 2021 December 31, 2020 (Unaudited) Customer A 81 % 33 % Customer B 17 % 67 %

Equity Method Investment (Table

Equity Method Investment (Tables)	6 Months Ended
	Jun. 30, 2021
Equity Method Investments and Joint Ventures [Abstract]
Summary of Investments	The following table summarizes our investment in HRT for the six months ended June 30, 2021 (in thousands): June 30, 2021 (Unaudited) Beginning balance $ 5,202 Investment in HRT — Remeasurement gain on HRT 269 Share of loss of HRT (760) Ending balance $ 4,711

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2021
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping	Our financial assets are considered Level 1 in the fair value hierarchy and measured at fair value, were as follows (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Assets Cash equivalents: Money market funds $ 11,316 $ 11,516 The financial liabilities subject to fair value measurement on a recurring basis, were as follows (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Financial Liabilities 3.00% – 2020 Convertible Notes $ 36,214 $ 32,106 8.00% – 2020 Convertible Notes 17,038 14,789 2020 Term Facility Loan 39,970 25,049 5.00% – $50.0 Million Convertible Notes 11,220 — 5.00% – $25.0 Million Convertible Notes 43,070 — 5.00% – $30.0 Million Convertible Notes 46,816 — Total financial liabilities $ 194,328 $ 71,944
Fair Value Measurement Inputs and Valuation Techniques	As of June 30, 2021, we measured fair value using a binomial lattice model (which is discussed in further detail below) with the following significant inputs: Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 48.45 % Conversion price discount 25 % Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 35 % Conversion price discount 40 % Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 35 % Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 48.4 % Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 48.4 % Fair Value per share of ordinary shares $24.70 Risk-free interest rate 0.03 % Expected volatility 55 % Expected term, in years 0.10 Discount yield 48.4 %
Fair Value, Liabilities Measured on Recurring and Nonrecurring Basis	We recorded a loss of $1.1 million and $4.1 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of the 3.00% Convertible Notes, as follows (in thousands): Fair value at December 31, 2020 $ 32,106 Plus: Loss from change in fair value $ 4,108 Fair value at June 30, 2021 $ 36,214 We recorded a loss of $0.5 million and $2.2 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of the 8.0% Convertible Notes, as follows (in thousands): Fair value at December 31, 2020 $ 14,789 Plus: Loss from change in fair value $ 2,249 Fair value at June 30, 2021 $ 17,038 We recorded a loss of $1.2 million and $14.9 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of 2020 Term Facility Loan, as follows (in thousands): Fair value at December 31, 2020 $ 25,049 Plus: Loss from change in fair value $ 14,921 Fair value at June 30, 2021 $ 39,970 We recorded a loss of $0.3 million and $0.9 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of 5.00%– $50.0 Million Convertible Note, as follows (in thousands): Fair value at January 11, 2021 $ 10,274 Plus: Loss from change in fair value $ 946 Fair value at June 30, 2021 $ 11,220 We recorded a loss of $1.3 million and $5.5 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with subsequent fair value remeasurement of the 5.00% – $25.0 Million Convertible Notes, as follows (in thousands): Fair value at December 31, 2020 $ 37,592 Plus: Loss from change in fair value $ 5,478 Fair value at June 30, 2021 $ 43,070 We recorded a loss of $1.4 million and $8.4 million for the three and six months ended June 30, 2021, respectively from a change in fair value of debt in connection with the subsequent fair value remeasurement of the 5.00% – $30.0 Million Convertible Notes, as follows (in thousands): Fair value at January 11, 2021 $ 38,403 Plus: Loss from change in fair value $ 8,413 Fair value at June 30, 2021 $ 46,816

Balance Sheet Components (Table

Balance Sheet Components (Tables)	6 Months Ended
	Jun. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Cash and Cash Equivalents	Cash and cash equivalents Cash and cash equivalents balances were concentrated by location as follows: As of June 30, 2021 December 31, 2020 (Unaudited) United Kingdom 92 % 96 % United States 7 % 3 % Other 1 % 1 %
Schedule of Other Receivables	Other receivables (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) R&D tax credit receivable $ 21,911 $ 17,412 Grants receivable 573 — VAT receivable 549 607 Other receivable 4 5 Total other receivables $ 23,037 $ 18,024
Schedule of Property, Plant and Equipment	Property and equipment, net (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Computer equipment $ 1,744 $ 1,218 Lab equipment 10,081 7,607 Motor vehicles 31 31 Furniture and fixtures 265 265 Leasehold improvements 704 704 Assets under construction 561 27 Total property and equipment $ 13,386 $ 9,852 Less: accumulated depreciation (7,162) (5,802) Total property and equipment, net $ 6,224 $ 4,050
Finance Lease, Right-Of-Use Assets	Finance lease right-of-use assets, net (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Finance lease right-of-use assets $ 2,966 $ 2,966 Less: accumulated amortization (1,020) (834) Total finance lease right-of-use assets, net $ 1,946 $ 2,132
Schedule of Intangible Assets, Net	Intangible assets, net (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) In-process research and development $ 3,048 $ 3,048 Total intangible assets, net $ 3,048 $ 3,048
Schedule of Other Non-current Assets	Other non-current assets (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Capitalized transaction costs $ 8,496 $ 121 Operating right of use assets $ 3,219 $ 1,486 Total other non-current assets $ 11,715 $ 1,607
Schedule of Accrued Expenses	Accrued expenses (in thousands): As of June 30, 2021 December 31, 2020 (Unaudited) Accrued bonus $ 2,926 $ 3,349 Accrued payroll and benefits 2,191 1,524 Accrued taxes 75 332 Accrued fabrication costs 2,304 2,321 Share appreciation rights 741 706 Other accrued expenses 3,867 2,163 Total accrued expenses $ 12,104 $ 10,395

Long Term Debt (Tables)

Long Term Debt (Tables)	6 Months Ended
	Jun. 30, 2021
Debt Disclosure [Abstract]
Schedule of Long-term Debt	The following table summarizes information relating to our long-term debt, (in thousands): June 30, 2021 (Unaudited) Principal Fair Value Net 3.00% – 2020 Convertible Notes $ 21,281 $ 14,933 $ 36,214 8.00% – 2020 Convertible Notes 8,000 9,038 17,038 2020 Term Facility Loan 33,949 6,021 39,970 5.00% – $50.0 Million Convertible Notes 10,274 946 11,220 5.00% – $25.0 Million Convertible Notes 25,000 18,070 43,070 5.00% – $30.0 Million Convertible Notes 30,000 16,816 46,816 Total long-term debt $ 128,504 $ 65,824 $ 194,328 Less: current portion of long-term debt — — — Long-term debt, net of current portion $ 128,504 $ 65,824 $ 194,328 December 31, 2020 Principal Fair Value Net 3.00% – 2020 Convertible Notes $ 21,281 $ 10,825 $ 32,106 8.00% – 2020 Convertible Notes 8,000 6,789 14,789 2020 Term Facility Loan 22,500 2,549 25,049 Paycheck Protection Program 2,860 — 2,860 Total long-term debt $ 54,641 $ 20,163 $ 74,804 Less: current portion of long-term debt — — — Long-term debt, net of current portion $ 54,641 $ 20,163 $ 74,804
Schedule of Future Maturities of Debt Agreements	Future minimum payments under the debt agreements as of June 30, 2021 are as follows (in thousands): Convertible 2021 (for the remaining period) $ — 2022 — 2023 — 2024 — 2025 114,179 Thereafter 50,274 Total future minimum payments $ 164,453 Less: current portion of debt principal — Non-current portion of debt principal $ 164,453

Earnings per Share (Tables)

Earnings per Share (Tables)	6 Months Ended
	Jun. 30, 2021
Earnings Per Share [Abstract]
Schedule of Net Loss Per Share, Basic and Diluted	The following is a calculation of basic and diluted net loss per share (in thousands, except for share and per share amounts): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) Basic and diluted: Net loss $ (30,557) $ (10,003) $ (95,334) $ (26,429) Weighted average ordinary shares 33,922,973 33,625,899 33,850,070 33,554,441 Basic and diluted net loss per share $ (0.90) $ (0.30) $ (2.82) $ (0.79)
Schedule of Antidilutive Securities Excluded from Computation of Net Loss Per Share	For the three and six months ended June 30, 2021 and 2020, we excluded the potential effect of the following in the calculation of the diluted loss per share, as the effect would be anti-dilutive due to losses incurred: Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) Outstanding warrants, less outstanding warrants with a $0.01 exercise price 899,698 842,717 899,698 842,717 Outstanding options (including performance options) 6,700,277 6,412,668 6,700,277 6,412,668 7,599,975 7,255,385 7,599,975 7,255,385

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2021
Share-based Payment Arrangement [Abstract]
Summary of Stock Option Activity	The following table summarizes the stock option activity related to the 2013 Share Option Plan : Number of Average Remaining Intrinsic (In thousands) Balances as of December 31, 2020 7,207,044 $ 4.94 6.75 $ 110,552 Options granted — $ — Options exercised (164,580) $ 1.72 Options forfeited (331,068) $ 10.30 Options expired (11,119) $ 6.66 Balances as of June 30, 2021 6,700,277 $ 4.75 6.16 $ 133,661 Options exercisable—June 30, 2021 4,989,774 $ 3.56 5.31 $ 105,483
Schedule of Stock-Based Compensation Expense	Stock-based compensation expense for all equity arrangements is included in the condensed consolidated statements of operations and comprehensive loss as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 ( Unaudited) ( Unaudited) Cost of revenue $ 363 $ 870 $ 631 $ 1,341 Research and development 1,171 1,330 2,219 2,081 Selling, general and administrative 442 345 851 767 Total stock-based compensation expense $ 1,976 $ 2,545 $ 3,701 $ 4,189
Summary of Warrant Information	The following table summarizes information related to our outstanding warrants. Investor Warrants in connection with the 8.00% – 2020 Convertible Notes and 5.00% – $25.0 Million Convertible Notes were excluded from the below table as they are classified as liabilities. Number of Weighted- Weighted- Balances as of December 31, 2020 1,013,103 $ 7.33 6.45 Warrants issued 18,694 $ 18.16 Warrants exercised (23,278) $ 0.00 Balances as of June 30, 2021 1,008,519 $ 7.70 5.78

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 2021
Leases [Abstract]
Summary of Operating Lease Information	The components of operating lease cost for the three and six months ended June 30, 2021 and 2020, were as follows (in thousands): Three Months Ended June 30, Six Months Ended June 30, 2021 2020 2021 2020 (Unaudited) (Unaudited) Operating Lease Cost: Fixed lease cost $ 292 213 $ 505 426 Variable lease cost 36 81 119 121 Total operating lease cost $ 328 $ 294 $ 624 $ 547 The supplemental cash flow information related to our operating leases is as follows (in thousands): Six Months Ended June 30, 2021 2020 Supplemental Cash Flow Information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 462 $ 454 Operating cash flows for finance leases $ — $ 12 Financing cash flows for finance leases $ — $ 933 Right-of-use assets obtained in exchange of lease obligations: Right-of-use assets obtained in exchange for new operating lease liabilities $ 2,187 $ —
Schedule of Maturity of Operating Lease Liabilities	Maturities of operating lease liabilities as of June 30, 2021, are as follows (in thousands): Operating Leases 2021 (for the remaining period) $ 582 2022 1,239 2023 931 2024 437 2025 327 Thereafter 394 Total lease obligation $ 3,910 Less: Imputed interest (408) Total lease liabilities $ 3,502 Less: Current lease liabilities (1,020) Total non-current lease liabilities $ 2,482

Supplemental Cash Flow Inform_2

Supplemental Cash Flow Information (Tables)	6 Months Ended
	Jun. 30, 2021
Supplemental Cash Flow Elements [Abstract]
Schedule of Supplemental Cash Flow Information	Non-cash operating, investing, and financing activities, and supplemental cash flow information are as follows (in thousands): Six Months Ended June 30, 2021 2020 (Unaudited) Supplemental Cash Flow Information: Interest paid $ 271 $ 45 Income tax paid $ 210 $ 80 Non-cash Operating Activities: Right-of-use assets obtained in exchange for new operating lease liabilities $ 2,187 $ — $ 2,187 0 Non-cash Investing Activities: Unpaid property and equipment received $ 1,163 $ 295 $ 1,163 $ 295 Non-cash Financing Activities: Unpaid deferred transaction costs $ 5,201 $ — Forgiveness of Paycheck Protection Program loan $ (2,860) $ — $ 2,341 $ —

Description of Business and S_3

Description of Business and Significant Accounting Policies (Details) - USD ($) $ in Thousands	Aug. 11, 2021	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accumulated deficit		$ 328,217		$ 232,883
Net cash used in operating activities		54,457	$ 13,106
Cash and cash equivalents		$ 35,395		$ 19,228
SC Health | Rockley Photonics Holdings Limited
Business Acquisition [Line Items]
Percentage of outstanding shares held in investment		1.40%
Rockley Photonics Limited | Rockley Photonics Holdings Limited
Business Acquisition [Line Items]
Percentage of outstanding shares held in investment		82.40%
Subsequent Event | SC Health | Rockley Photonics Holdings Limited
Business Acquisition [Line Items]
Percentage of outstanding shares held in investment	9.80%
Subsequent Event | Rockley Photonics Limited | Rockley Photonics Holdings Limited
Business Acquisition [Line Items]
Percentage of outstanding shares held in investment	82.30%
The Business Combination | Subsequent Event | Rockley Photonics Holdings Limited
Business Acquisition [Line Items]
Proceeds from business combination	$ 168,000

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Concentration Risk [Line Items]
Revenue	$ 2,195	$ 7,881	$ 3,966	$ 14,544
Revenue | Customer Concentration Risk | Customer A
Concentration Risk [Line Items]
Concentration risk	100.00%	69.00%	100.00%	83.00%
Revenue | Customer Concentration Risk | Customer B
Concentration Risk [Line Items]
Concentration risk	0.00%	31.00%	0.00%	17.00%
Accounts Receivable | Customer Concentration Risk | Customer A
Concentration Risk [Line Items]
Concentration risk			81.00%		33.00%
Accounts Receivable | Customer Concentration Risk | Customer B
Concentration Risk [Line Items]
Concentration risk			17.00%		67.00%
United States
Concentration Risk [Line Items]
Revenue	$ 2,195	$ 5,423	$ 3,966	$ 12,086
Rest of World
Concentration Risk [Line Items]
Revenue	$ 0	$ 2,458	$ 0	$ 2,458

Equity Method Investment (Detai

Equity Method Investment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Equity Method Investment
Beginning balance			$ 5,202
Investment in equity method investee			0	$ 2,500
Share of loss of HRT	$ (597)	$ (102)	(760)	$ (252)
Ending balance	$ 4,711		$ 4,711
HRT | Variable Interest Entity
Schedule of Equity Method Investments [Line Items]
Equity method investment, ownership percentage	24.90%		24.90%
Equity Method Investment
Beginning balance			$ 5,202
Investment in equity method investee			0
Remeasurement gain on HRT			269
Share of loss of HRT			(760)
Ending balance	$ 4,711		$ 4,711

Fair Value Measurements - Finan

Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Plus: Loss from change in fair value	$ 6,008,000	$ (312,000)	$ 45,661,000		$ 2,222,000
Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	5.00%		5.00%	5.00%
3.00% – 2020 Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 36,200,000		$ 36,200,000	$ 36,200,000
3.00% – 2020 Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	0.03%		0.03%	0.03%
Debt instrument, principal amount	$ 21,300,000		$ 21,300,000	$ 21,300,000
Plus: Loss from change in fair value	1,100,000		4,108,000
8.00% – 2020 Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 17,000,000		$ 17,000,000	$ 17,000,000
8.00% – 2020 Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	0.08%		0.08%	0.08%
Debt instrument, principal amount	$ 8,000,000		$ 8,000,000	$ 8,000,000
Plus: Loss from change in fair value	500,000		2,249,000
5.00% – $50.0 Million Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 11,200,000		$ 11,200,000	$ 11,200,000
5.00% – $50.0 Million Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	5.00%		5.00%	5.00%
Debt instrument, principal amount	$ 50,000,000		$ 50,000,000	$ 50,000,000
Plus: Loss from change in fair value	300,000		900,000	946,000
5.00% – $25.0 Million Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 43,100,000		$ 43,100,000	$ 43,100,000
5.00% – $25.0 Million Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	5.00%		5.00%	5.00%
Debt instrument, principal amount	$ 25,000,000		$ 25,000,000	$ 25,000,000
Plus: Loss from change in fair value	1,300,000		5,478,000
5.00% – $30.0 Million Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 46,800,000		$ 46,800,000	$ 46,800,000
5.00% – $30.0 Million Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	5.00%		5.00%	5.00%
Debt instrument, principal amount	$ 30,000,000		$ 30,000,000	$ 30,000,000
Plus: Loss from change in fair value	1,400,000		8,400,000	8,413,000
Level 1 | Money Market Funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money market funds	11,316,000	$ 11,516,000	11,316,000	11,316,000	$ 11,516,000
Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
2020 Term Facility Loan	39,970,000		39,970,000	39,970,000		$ 25,049,000
Total financial liabilities	194,328,000		194,328,000	194,328,000		71,944,000
Level 3 | 3.00% – 2020 Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	36,214,000		36,214,000	36,214,000		32,106,000
Level 3 | 8.00% – 2020 Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	17,038,000		17,038,000	17,038,000		14,789,000
Level 3 | 5.00% – $50.0 Million Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	11,220,000		11,220,000	11,220,000		0
Level 3 | 5.00% – $25.0 Million Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	43,070,000		43,070,000	43,070,000		0
Level 3 | 5.00% – $30.0 Million Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 46,816,000		$ 46,816,000	$ 46,816,000		$ 0

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Significant Measurement Inputs (Details) - Level 3	Jun. 30, 2021year$ / shares
Convertible Notes | 3.00% – 2020 Convertible Notes | Fair Value per share of ordinary shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | $ / shares	24.70
Convertible Notes | 3.00% – 2020 Convertible Notes | Risk-free interest rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.0003
Convertible Notes | 3.00% – 2020 Convertible Notes | Expected volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.55
Convertible Notes | 3.00% – 2020 Convertible Notes | Expected term, in years
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | year	0.10
Convertible Notes | 3.00% – 2020 Convertible Notes | Discount yield
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.4845
Convertible Notes | 3.00% – 2020 Convertible Notes | Conversion price discount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.25
Convertible Notes | 8.00% – 2020 Convertible Notes | Fair Value per share of ordinary shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | $ / shares	24.70
Convertible Notes | 8.00% – 2020 Convertible Notes | Risk-free interest rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.0003
Convertible Notes | 8.00% – 2020 Convertible Notes | Expected volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.55
Convertible Notes | 8.00% – 2020 Convertible Notes | Expected term, in years
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | year	0.10
Convertible Notes | 8.00% – 2020 Convertible Notes | Discount yield
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.35
Convertible Notes | 8.00% – 2020 Convertible Notes | Conversion price discount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.40
Convertible Notes | 5.00% – $50.0 Million Convertible Notes | Fair Value per share of ordinary shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | $ / shares	24.70
Convertible Notes | 5.00% – $50.0 Million Convertible Notes | Risk-free interest rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.0003
Convertible Notes | 5.00% – $50.0 Million Convertible Notes | Expected volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.55
Convertible Notes | 5.00% – $50.0 Million Convertible Notes | Expected term, in years
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | year	0.10
Convertible Notes | 5.00% – $50.0 Million Convertible Notes | Discount yield
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.484
Convertible Notes | 5.00% – $25.0 Million Convertible Notes | Fair Value per share of ordinary shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | $ / shares	24.70
Convertible Notes | 5.00% – $25.0 Million Convertible Notes | Risk-free interest rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.0003
Convertible Notes | 5.00% – $25.0 Million Convertible Notes | Expected volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.55
Convertible Notes | 5.00% – $25.0 Million Convertible Notes | Expected term, in years
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | year	0.10
Convertible Notes | 5.00% – $25.0 Million Convertible Notes | Discount yield
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.484
Convertible Notes | 5.00% – $30.0 Million Convertible Notes | Fair Value per share of ordinary shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | $ / shares	24.70
Convertible Notes | 5.00% – $30.0 Million Convertible Notes | Risk-free interest rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.0003
Convertible Notes | 5.00% – $30.0 Million Convertible Notes | Expected volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.55
Convertible Notes | 5.00% – $30.0 Million Convertible Notes | Expected term, in years
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | year	0.10
Convertible Notes | 5.00% – $30.0 Million Convertible Notes | Discount yield
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.484
2020 Term Facility Loan | Fair Value per share of ordinary shares
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | $ / shares	24.70
2020 Term Facility Loan | Risk-free interest rate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.0003
2020 Term Facility Loan | Expected volatility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.55
2020 Term Facility Loan | Expected term, in years
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input | year	0.10
2020 Term Facility Loan | Discount yield
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, measurement input	0.35

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt	$ 128,504,000		$ 128,504,000	$ 128,504,000		$ 54,641,000
Gain (loss) on debt instrument	$ (6,008,000)	$ 312,000	$ (45,661,000)		$ (2,222,000)
Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	5.00%		5.00%	5.00%
2020 Term Facility Loan
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, principal amount	$ 35,000,000		$ 35,000,000	$ 35,000,000
Long-term debt	33,949,000		33,949,000	33,949,000		22,500,000
Convertible notes	40,000,000		40,000,000	40,000,000
Gain (loss) on debt instrument	(1,200,000)		(14,921,000)
3.00% – 2020 Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 36,200,000		$ 36,200,000	$ 36,200,000
3.00% – 2020 Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	0.03%		0.03%	0.03%
Debt instrument, principal amount	$ 21,300,000		$ 21,300,000	$ 21,300,000
Long-term debt	21,281,000		21,281,000	21,281,000		21,281,000
Gain (loss) on debt instrument	(1,100,000)		(4,108,000)
8.00% – 2020 Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 17,000,000		$ 17,000,000	$ 17,000,000
8.00% – 2020 Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	0.08%		0.08%	0.08%
Debt instrument, principal amount	$ 8,000,000		$ 8,000,000	$ 8,000,000
Long-term debt	8,000,000		8,000,000	8,000,000		$ 8,000,000
Gain (loss) on debt instrument	(500,000)		(2,249,000)
5.00% – $50.0 Million Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 11,200,000		$ 11,200,000	$ 11,200,000
5.00% – $50.0 Million Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	5.00%		5.00%	5.00%
Debt instrument, principal amount	$ 50,000,000		$ 50,000,000	$ 50,000,000
Long-term debt	10,274,000		10,274,000	10,274,000
Gain (loss) on debt instrument	(300,000)		(900,000)	(946,000)
Debt instrument, convertible, denominator used to calculate conversion price at maturity date, amount	1,500,000,000		1,500,000,000	1,500,000,000
5.00% – $25.0 Million Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 43,100,000		$ 43,100,000	$ 43,100,000
5.00% – $25.0 Million Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	5.00%		5.00%	5.00%
Debt instrument, principal amount	$ 25,000,000		$ 25,000,000	$ 25,000,000
Long-term debt	25,000,000		25,000,000	25,000,000
Gain (loss) on debt instrument	(1,300,000)		(5,478,000)
Debt instrument, convertible, denominator used to calculate conversion price at maturity date, amount	675,000,000		675,000,000	675,000,000
5.00% – $30.0 Million Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Convertible notes	$ 46,800,000		$ 46,800,000	$ 46,800,000
5.00% – $30.0 Million Convertible Notes | Convertible Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt instrument, stated percentage	5.00%		5.00%	5.00%
Debt instrument, principal amount	$ 30,000,000		$ 30,000,000	$ 30,000,000
Long-term debt	30,000,000		30,000,000	30,000,000
Gain (loss) on debt instrument	(1,400,000)		(8,400,000)	(8,413,000)
Debt instrument, convertible, denominator used to calculate conversion price at maturity date, amount	$ 800,000,000		$ 800,000,000	$ 800,000,000

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Plus: Loss from change in fair value	$ 6,008	$ (312)	$ 45,661		$ 2,222
2020 Term Facility Loan
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance			25,049
Plus: Loss from change in fair value	1,200		14,921
Ending balance	39,970		39,970	$ 39,970
3.00% – 2020 Convertible Notes | Convertible Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance			32,106
Plus: Loss from change in fair value	1,100		4,108
Ending balance	36,214		36,214	36,214
8.00% – 2020 Convertible Notes | Convertible Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance			14,789
Plus: Loss from change in fair value	500		2,249
Ending balance	17,038		17,038	17,038
5.00% – $50.0 Million Convertible Notes | Convertible Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance				10,274
Plus: Loss from change in fair value	300		900	946
Ending balance	11,220		11,220	11,220
5.00% – $25.0 Million Convertible Notes | Convertible Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance			37,592
Plus: Loss from change in fair value	1,300		5,478
Ending balance	43,070		43,070	43,070
5.00% – $30.0 Million Convertible Notes | Convertible Notes
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance				38,403
Plus: Loss from change in fair value	1,400		8,400	8,413
Ending balance	$ 46,816		$ 46,816	$ 46,816

Balance Sheet Components - Cash

Balance Sheet Components - Cash and Cash Equivalents (Details) - Cash and Cash Equivalents - Geographic Concentration Risk	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
United Kingdom
Cash and Cash Equivalents [Line Items]
Concentration risk	92.00%	96.00%
United States
Cash and Cash Equivalents [Line Items]
Concentration risk	7.00%	3.00%
Other
Cash and Cash Equivalents [Line Items]
Concentration risk	1.00%	1.00%

Balance Sheet Components - Othe

Balance Sheet Components - Other Receivables (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
R&D tax credit receivable	$ 21,911	$ 17,412
Grants receivable	573	0
VAT receivable	549	607
Other receivables	4	5
Total other receivables	$ 23,037	$ 18,024

Balance Sheet Components - Long

Balance Sheet Components - Long Lived Assets (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 13,386		$ 13,386		$ 9,852
Less: accumulated depreciation	(7,162)		(7,162)		(5,802)
Total property and equipment, net	6,224		6,224		4,050
Depreciation	1,000	$ 600	1,800	$ 1,200
Finance lease right-of-use assets	2,966		2,966		2,966
Less: accumulated amortization	(1,020)		(1,020)		(834)
Total finance lease right-of-use assets, net	$ 1,946		$ 1,946		$ 2,132
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, equipment, and finance lease right-of-use assets, net		Property, equipment, and finance lease right-of-use assets, net		Property, equipment, and finance lease right-of-use assets, net
Amortization	$ 100	$ 100	$ 200	$ 200
Computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	1,744		1,744		$ 1,218
Lab equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	10,081		10,081		7,607
Motor vehicles
Property, Plant and Equipment [Line Items]
Total property and equipment	31		31		31
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	265		265		265
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	704		704		704
Assets under construction
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 561		$ 561		$ 27

Balance Sheet Components - Sche

Balance Sheet Components - Schedule of Intangible Assets, Net (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Indefinite-lived Intangible Assets [Line Items]
Intangible assets, net	$ 3,048	$ 3,048
In-process research and development
Indefinite-lived Intangible Assets [Line Items]
Intangible assets, net	$ 3,048	$ 3,048

Balance Sheet Components - Sc_2

Balance Sheet Components - Schedule of Other Non-current Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Capitalized transaction costs	$ 8,496	$ 121
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Other non-current assets	Other non-current assets
Operating right of use assets	$ 3,219	$ 1,486
Other non-current assets	$ 11,715	$ 1,607

Balance Sheet Components - Sc_3

Balance Sheet Components - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued bonus	$ 2,926	$ 3,349
Accrued payroll and benefits	2,191	1,524
Accrued taxes	75	332
Accrued fabrication costs	2,304	2,321
Share appreciation rights	741	706
Other accrued expenses	3,867	2,163
Accrued expenses	$ 12,104	$ 10,395

Long Term Debt - Summary of Lon

Long Term Debt - Summary of Long Term Debt (Details) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Principal
Total long-term debt	$ 128,504,000	$ 54,641,000
Less: current portion of long-term debt	0	0
Non-current portion of debt principal	128,504,000	54,641,000
Fair Value Adjustment
Total long-term debt	65,824,000	20,163,000
Less: current portion of long-term debt	0	0
Long-term debt, net of current portion	65,824,000	20,163,000
Net
Total long-term debt	194,328,000	74,804,000
Less: current portion of long-term debt	0	0
Long-term debt	$ 194,328,000	74,804,000
Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage	5.00%
Principal
Less: current portion of long-term debt	$ 0
Non-current portion of debt principal	$ 164,453,000
Convertible Notes | 3.00% – 2020 Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage	0.03%
Debt instrument, principal amount	$ 21,300,000
Principal
Total long-term debt	21,281,000	21,281,000
Fair Value Adjustment
Total long-term debt	14,933,000	10,825,000
Net
Total long-term debt	$ 36,214,000	32,106,000
Convertible Notes | 8.00% – 2020 Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage	0.08%
Debt instrument, principal amount	$ 8,000,000
Principal
Total long-term debt	8,000,000	8,000,000
Fair Value Adjustment
Total long-term debt	9,038,000	6,789,000
Net
Total long-term debt	$ 17,038,000	14,789,000
Convertible Notes | 5.00% – $50.0 Million Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage	5.00%
Debt instrument, principal amount	$ 50,000,000
Principal
Total long-term debt	10,274,000
Fair Value Adjustment
Total long-term debt	946,000
Net
Total long-term debt	$ 11,220,000
Convertible Notes | 5.00% – $25.0 Million Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage	5.00%
Debt instrument, principal amount	$ 25,000,000
Principal
Total long-term debt	25,000,000
Fair Value Adjustment
Total long-term debt	18,070,000
Net
Total long-term debt	$ 43,070,000
Convertible Notes | 5.00% – $30.0 Million Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage	5.00%
Debt instrument, principal amount	$ 30,000,000
Principal
Total long-term debt	30,000,000
Fair Value Adjustment
Total long-term debt	16,816,000
Net
Total long-term debt	46,816,000
2020 Term Facility Loan
Debt Instrument [Line Items]
Debt instrument, principal amount	35,000,000
Principal
Total long-term debt	33,949,000	22,500,000
Fair Value Adjustment
Total long-term debt	6,021,000	2,549,000
Net
Total long-term debt	$ 39,970,000	25,049,000
Paycheck Protection Program
Principal
Total long-term debt		2,860,000
Fair Value Adjustment
Total long-term debt		0
Net
Total long-term debt		$ 2,860,000

Long Term Debt - Schedule of Fu

Long Term Debt - Schedule of Future Minimum Payments (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Less: current portion of long-term debt	$ 0	$ 0
Non-current portion of debt principal	128,504	$ 54,641
Convertible Notes
Debt Instrument [Line Items]
2021 (for the remaining period)	0
2022	0
2023	0
2024	0
2025	114,179
Thereafter	50,274
Long-term debt, net of current portion	164,453
Less: current portion of long-term debt	0
Non-current portion of debt principal	$ 164,453

Long Term Debt - Narrative (Det

Long Term Debt - Narrative (Details) - USD ($)	Dec. 31, 2020	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	May 25, 2021
Debt Instrument [Line Items]
Gain (loss) on debt instrument			$ (6,008,000)	$ 312,000	$ (45,661,000)		$ (2,222,000)
Long-term debt	$ 54,641,000	$ 128,504,000	$ 128,504,000		$ 128,504,000	$ 128,504,000
Warrants issued (in shares)					18,694
Warrants outstanding, exercise price (in dollars per share)		$ 0.01	$ 0.01		$ 0.01	$ 0.01
Forgiveness of Paycheck Protection Program loan		$ 2,900,000	$ 2,860,000	0	$ 2,860,000		0
Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage		5.00%	5.00%		5.00%	5.00%
Convertible Notes | 3.00% – 2020 Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage		0.03%	0.03%		0.03%	0.03%
Unpaid interest			$ 100,000	0	$ 300,000		0
Gain (loss) on debt instrument			(1,100,000)		(4,108,000)
Long-term debt	21,281,000	$ 21,281,000	21,281,000		21,281,000	$ 21,281,000
Debt instrument, principal amount		$ 21,300,000	$ 21,300,000		$ 21,300,000	$ 21,300,000
Convertible Notes | 8.00% – 2020 Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage		0.08%	0.08%		0.08%	0.08%
Unpaid interest			$ 200,000	$ 100,000	$ 300,000		$ 200,000
Gain (loss) on debt instrument			(500,000)		(2,249,000)
Long-term debt	$ 8,000,000	$ 8,000,000	8,000,000		8,000,000	$ 8,000,000
Debt instrument, principal amount		$ 8,000,000	$ 8,000,000		$ 8,000,000	$ 8,000,000
Convertible Notes | 5.00% – $50.0 Million Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage		5.00%	5.00%		5.00%	5.00%
Unpaid interest			$ 100,000		$ 300,000
Gain (loss) on debt instrument			(300,000)		(900,000)	$ (946,000)
Long-term debt		$ 10,274,000	10,274,000		10,274,000	10,274,000
Debt instrument, principal amount		50,000,000	50,000,000		50,000,000	50,000,000
Proceeds from equity triggering debt conversion, minimum, amount		$ 25,000,000	$ 25,000,000		$ 25,000,000	$ 25,000,000
Debt instrument, convertible, conversion price, discount		15.00%	15.00%		15.00%	15.00%
Debt instrument, convertible, denominator used to calculate conversion price, amount		$ 1,500,000,000	$ 1,500,000,000		$ 1,500,000,000	$ 1,500,000,000
Debt instrument, convertible, denominator used to calculate conversion price at maturity date, amount		$ 1,500,000,000	$ 1,500,000,000		$ 1,500,000,000	$ 1,500,000,000
Convertible Notes | 5.00% – $25.0 Million Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage		5.00%	5.00%		5.00%	5.00%
Unpaid interest			$ 300,000		$ 600,000
Gain (loss) on debt instrument			(1,300,000)		(5,478,000)
Long-term debt		$ 25,000,000	25,000,000		25,000,000	$ 25,000,000
Debt instrument, principal amount		25,000,000	25,000,000		25,000,000	25,000,000
Proceeds from equity triggering debt conversion, minimum, amount		$ 25,000,000	$ 25,000,000		$ 25,000,000	$ 25,000,000
Debt instrument, convertible, conversion price, discount		25.00%	25.00%		25.00%	25.00%
Debt instrument, convertible, denominator used to calculate conversion price, amount		$ 800,000,000	$ 800,000,000		$ 800,000,000	$ 800,000,000
Debt instrument, convertible, denominator used to calculate conversion price at maturity date, amount		$ 675,000,000	$ 675,000,000		$ 675,000,000	$ 675,000,000
Debt instrument, conversion price					100.00%
Warrants issued (in shares)	278,775
Warrants outstanding, stated rate		5.00%	5.00%		5.00%	5.00%
Warrants outstanding, exercise price (in dollars per share)		$ 0.00001	$ 0.00001		$ 0.00001	$ 0.00001
Convertible Notes | 5.00% – $30.0 Million Convertible Notes
Debt Instrument [Line Items]
Debt instrument, stated percentage		5.00%	5.00%		5.00%	5.00%
Unpaid interest			$ 400,000		$ 700,000
Gain (loss) on debt instrument			(1,400,000)		(8,400,000)	$ (8,413,000)
Long-term debt		$ 30,000,000	30,000,000		30,000,000	30,000,000
Debt instrument, principal amount		30,000,000	30,000,000		30,000,000	30,000,000
Proceeds from equity triggering debt conversion, minimum, amount		$ 25,000,000	$ 25,000,000		$ 25,000,000	$ 25,000,000
Debt instrument, convertible, conversion price, discount		25.00%	25.00%		25.00%	25.00%
Debt instrument, convertible, denominator used to calculate conversion price, amount		$ 800,000,000	$ 800,000,000		$ 800,000,000	$ 800,000,000
Debt instrument, convertible, denominator used to calculate conversion price at maturity date, amount		800,000,000	800,000,000		800,000,000	800,000,000
2020 Term Facility Loan
Debt Instrument [Line Items]
Gain (loss) on debt instrument			(1,200,000)		(14,921,000)
Interest paid			200,000		300,000
Long-term debt	$ 22,500,000	33,949,000	33,949,000		33,949,000	33,949,000
Debt instrument, portion to be converted to equity								30.00%
Debt instrument, portion to be repaid								70.00%
Debt instrument, principal amount		$ 35,000,000	$ 35,000,000		$ 35,000,000	$ 35,000,000

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Provision for income tax	$ 110	$ 80	$ 210	$ 220
Effective income tax rate, percent (less than)	1.00%	1.00%	1.00%	1.00%

Ordinary Shares (Details)

Ordinary Shares (Details) - USD ($) $ / shares in Units, $ in Thousands	Jun. 30, 2021	Mar. 11, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Ordinary shares, par value (in dollars per share)	$ 0.00001		$ 0.00001
Rockley Photonics Holdings Limited
Class of Stock [Line Items]
Additional paid in capital	$ 50	$ 50
Rockley Photonics Holdings Limited | Ordinary Shares
Class of Stock [Line Items]
Shares issued (in shares)		1
Ordinary shares, par value (in dollars per share)		$ 0.00001

Earnings per Share - Net Loss A

Earnings per Share - Net Loss Available to Ordinary Shareholders (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net loss, basic	$ (30,557)	$ (10,003)	$ (95,334)	$ (26,429)
Net loss, diluted	$ (30,557)	$ (10,003)	$ (95,334)	$ (26,429)
Weighted-average shares outstanding, basic (in shares)	33,922,973	33,625,899	33,850,070	33,554,441
Weighted-average shares outstanding, diluted (in shares)	33,922,973	33,625,899	33,850,070	33,554,441
Net loss per share, basic (in dollars per share)	$ (0.90)	$ (0.30)	$ (2.82)	$ (0.79)
Net loss per share, diluted (in dollars per share)	$ (0.90)	$ (0.30)	$ (2.82)	$ (0.79)

Earnings per Share - Summary of

Earnings per Share - Summary of Anti-dilutive Securities (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Warrants outstanding (in shares)	1,008,519		1,008,519		1,013,103
Warrants outstanding, exercise price (in dollars per share)	$ 0.01		$ 0.01
Antidilutive securities (in shares)	7,599,975,000	7,255,385,000	7,599,975,000	7,255,385,000
$0.01 Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Warrants outstanding (in shares)	108,821	132,099	108,821	132,099
Warrants outstanding, exercise price (in dollars per share)	$ 0.01	$ 0.01	$ 0.01	$ 0.01
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	899,698,000	842,717,000	899,698,000	842,717,000
Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities (in shares)	6,700,277,000	6,412,668,000	6,700,277,000	6,412,668,000

Stock-Based Compensation - Narr

Stock-Based Compensation - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share appreciation rights	$ 741,000		$ 741,000		$ 706,000
Unrecognized compensation expense, options	11,900,000		11,900,000
Total stock-based compensation expense	1,976,000	$ 2,545,000	3,701,000	$ 4,189,000
Unrecognized compensation expense	$ 1,000,000		$ 1,000,000		1,200,000
Convertible Notes
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Debt instrument, stated percentage	5.00%		5.00%
8.00% – 2020 Convertible Notes | Convertible Notes
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Debt instrument, stated percentage	0.08%		0.08%
Debt instrument, principal amount	$ 8,000,000		$ 8,000,000
5.00% – $25.0 Million Convertible Notes | Convertible Notes
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Debt instrument, stated percentage	5.00%		5.00%
Debt instrument, principal amount	$ 25,000,000		$ 25,000,000
Share Appreciation Rights
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share appreciation rights	$ 700,000		$ 700,000		$ 700,000
Share-based compensation fair value (in dollars per share)	$ 24.70		$ 24.70		$ 20.28
Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	11,458,989		11,458,989
Number of shares available for grant (in shares)	3,088,276		3,088,276
Unrecognized compensation expense, period for recognition			1 year 2 months 12 days
Performance Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 100,000	$ 20,000	$ 200,000	$ 100,000

Stock-Based Compensation - Stoc

Stock-Based Compensation - Stock Option Activity (Details) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2021USD ($)$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares
Number of Options Outstanding
Beginning balance (in shares) | shares	7,207,044,000
Options granted (in shares) | shares	0
Options exercised (in shares) | shares	(164,580,000)
Options forfeited (in shares) | shares	(331,068,000)
Options expired (in shares) | shares	(11,119,000)
Ending balance (in shares) | shares	6,700,277,000	7,207,044,000
Options exercisable (in shares) | shares	4,989,774,000
Average Exercise Price Per Share
Beginning balance (in dollars per share) | $ / shares	$ 4.94
Options granted (in dollars per share) | $ / shares	0
Options exercised (in dollars per share) | $ / shares	1.72
Options forfeited (in dollars per share) | $ / shares	10.30
Options expired (in dollars per share) | $ / shares	6.66
Ending balance (in dollars per share) | $ / shares	4.75	$ 4.94
Options exercisable (in dollars per share) | $ / shares	$ 3.56
Options outstanding, remaining contractual life	6 years 1 month 28 days	6 years 9 months
Options exercisable, remaining contractual life	5 years 3 months 21 days
Options outstanding, intrinsic value | $	$ 133,661	$ 110,552
Options exercisable, intrinsic value | $	$ 105,483

Stock-Based Compensation - St_2

Stock-Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 1,976	$ 2,545	$ 3,701	$ 4,189
Cost of revenue
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	363	870	631	1,341
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1,171	1,330	2,219	2,081
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 442	$ 345	$ 851	$ 767

Stock-Based Compensation - Sche

Stock-Based Compensation - Schedule of Outstanding Warrants (Details) - $ / shares	Dec. 31, 2020	Jun. 30, 2021
Number of Warrants Outstanding
Beginning balance (in shares)		1,013,103
Warrants issued (in shares)		18,694
Warrants exercised (in shares)		(23,278)
Ending balance (in shares)	1,013,103	1,008,519
Average Exercise Price Per Share
Beginning balance (in dollars per share)		$ 7.33
Warrants issued (in dollars per share)		18.16
Warrants exercised (in dollars per share)		0
Ending balance (in dollars per share)	$ 7.33	$ 7.70
Weighted- Average Contractual Life (Years)	6 years 5 months 12 days	5 years 9 months 10 days

Related Party Transactions (Det

Related Party Transactions (Details) - Variable Interest Entity - HRT - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Related Party Transaction [Line Items]
Sales to related parties	$ 0	$ 2,500,000	$ 0	$ 2,500,000
Accounts receivable, related parties, current	400,000		400,000		$ 3,300,000
Accounts payable, related parties, current	$ 0		$ 0

Leases - Additional Information

Leases - Additional Information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Leases [Abstract]
Operating lease, weighted average remaining lease term	3 years		3 years
Operating lease, weighted average discount rate	6.00%		6.00%
Operating Lease Cost:
Fixed lease cost	$ 292	$ 213	$ 505	$ 426
Variable lease cost	36	81	119	121
Total operating lease cost	$ 328	$ 294	624	547
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases			462	454
Operating cash flows for finance leases			0	12
Principal payments on finance lease			0	933
Right-of-use assets obtained in exchange of lease obligations:
Right-of-use assets obtained in exchange for new operating lease liabilities			$ 2,187	$ 0

Leases - Schedule of Maturities

Leases - Schedule of Maturities of Operating Leases (Details) $ in Thousands	Jun. 30, 2021USD ($)
Leases [Abstract]
2021 (for the remaining period)	$ 582
2022	1,239
2023	931
2024	437
2025	327
Thereafter	394
Total lease obligation	3,910
Less: Imputed interest	(408)
Total lease liabilities	$ 3,502
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other current liabilities
Less: Current lease liabilities	$ (1,020)
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other long-term liabilities
Total non-current lease liabilities	$ 2,482

Commitment and Contingencies (D

Commitment and Contingencies (Details) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Contractual obligations	$ 8.1	$ 3

Defined Contribution Plan (Deta

Defined Contribution Plan (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Retirement Benefits [Abstract]
Defined contribution plan, employer contributions	$ 0.2	$ 0.1	$ 0.4	$ 0.3

Supplemental Cash Flow Inform_3

Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Supplemental Cash Flow Information:
Interest paid				$ 271	$ 45
Income tax paid				210	80
Non-cash Operating Activities:
Right-of-use assets obtained in exchange for new operating lease liabilities				2,187	0
Total non-cash operating activities				2,187	0
Non-cash Investing Activities:
Unpaid property and equipment received				1,163	295
Total non-cash investing activities				1,163	295
Non-cash Financing Activities:
Unpaid deferred transaction costs				5,201	0
Forgiveness of Paycheck Protection Program loan	$ (2,900)	$ (2,860)	$ 0	(2,860)	0
Total non-cash financing activities				$ 2,341	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	Aug. 12, 2021	Aug. 11, 2021	Aug. 09, 2021	Jun. 30, 2021	May 25, 2021
Rockley Photonics Holdings Limited | SC Health
Subsequent Event [Line Items]
Percentage of outstanding shares held in investment				1.40%
Rockley Photonics Holdings Limited | Rockley Photonics Limited
Subsequent Event [Line Items]
Percentage of outstanding shares held in investment				82.40%
2020 Term Facility Loan
Subsequent Event [Line Items]
Debt instrument, portion to be converted to equity					30.00%
Debt instrument, portion to be repaid					70.00%
Subsequent Event | Rockley Photonics Holdings Limited
Subsequent Event [Line Items]
Proceeds from sale of equity		$ 126.9
Subsequent Event | Rockley Photonics Holdings Limited | SC Health
Subsequent Event [Line Items]
Investment owned (in shares)		12,339,650
Percentage of outstanding shares held in investment		9.80%
Subsequent Event | Rockley Photonics Holdings Limited | Rockley Photonics Limited
Subsequent Event [Line Items]
Investment owned (in shares)		103,916,607
Percentage of outstanding shares held in investment		82.30%
Subsequent Event | 2020 Term Facility Loan
Subsequent Event [Line Items]
Debt instrument, portion to be converted to equity		30.00%
Debt instrument, portion to be repaid		70.00%
Subsequent Event | The Business Combination
Subsequent Event [Line Items]
Business combination, conversion price per acquiree share (in dollars per share)			$ 10
Service fees incurred	$ 29.3
Unpaid professional fees	$ 14.8
Subsequent Event | The Business Combination | Rockley Photonics Holdings Limited
Subsequent Event [Line Items]
Business combination, conversion price per acquiree share (in dollars per share)			$ 10