Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Summary of Assets and Liabilities That Are Measured at Fair Value on Recurring Basis

The following tables present information about the Company’s financial assets and liabilities measured at fair value on a recurring basis (in thousands):

		As of December 31, 2023
	Classification	Total		Level 1		Level 2		Level 3
Assets:
Money market funds	Cash and cash equivalents	$	913,729	$	913,729	$	—	$	—
Synlogic, Inc. warrants (1)	Investments	654		—		654		—
Marketable equity securities (2)	Investments	19,190		18,401		789		—
Notes receivable	Prepaid expenses and other current assets	12,293		—		—		12,293
Notes receivable	Other non-current assets	13,601		—		11,765		1,836
Total assets		$	959,467	$	932,130	$	13,208	$	14,129
Liabilities:
Public Warrants	Warrant liabilities	$	3,794	$	3,794	$	—	$	—
Private Placement Warrants	Warrant liabilities	1,906		—		60		1,846
Contingent consideration	Accrued expenses and other current liabilities	18,468		—		—		18,468
Contingent consideration	Other non-current liabilities	5,805		—		—		5,805
Total liabilities		$	29,973	$	3,794	$	60	$	26,119

		As of December 31, 2022
	Classification	Total		Level 1		Level 2		Level 3
Assets:
Money market funds	Cash and cash equivalents	$	1,089,026	$	1,089,026	$	—	$	—
Synlogic, Inc. warrants (1)	Investments	1,937		—		1,937		—
Marketable equity securities (2)	Investments	25,714		21,312		4,402		—
Notes receivable	Other non-current assets	37,660		—		30,000		7,660
Total assets		$	1,154,337	$	1,110,338	$	36,339	$	7,660
Liabilities:
Public Warrants	Warrant liabilities	$	6,900	$	6,900	$	—	$	—
Private Placement Warrants	Warrant liabilities	3,968		—		108		3,860
Contingent consideration	Accrued expenses and other current liabilities	6,378		—		—		6,378
Contingent consideration	Other non-current liabilities	18,095		—		—		18,095
Total liabilities		$	35,341	$	6,900	$	108	$	28,333

(1)The fair value of Synlogic, Inc. warrants is calculated as the quoted price of the underlying common stock, less the unpaid exercise price of the warrants.

(2)Marketable equity securities classified as Level 2 reflect a discount for lack of marketability due to regulatory sales restrictions.

Summary of Fair Value Measurements Inputs

The following table provides quantitative information regarding Level 3 inputs used in the recurring valuation of the Private Placement Warrants as of their measurement dates:

	December 31, 2023			December 31, 2022
Exercise price	$	11.50		$	11.50
Stock price	$	1.69		$	1.69
Volatility	70.5		%	71.5		%
Term (in years)	2.71			3.71
Risk-free interest rate	4.01		%	4.11		%

The following table provides quantitative information regarding Level 3 inputs used in the fair value measurements of contingent consideration liabilities as of the periods presented:

Contingent Consideration Liability	Valuation Technique	Unobservable Input	December 31, 2023 Range		December 31, 2022 Range
Earnout payments (FGen, Dutch DNA and Altar acquisitions) (1)	Probability-weighted present value	Probability of payment	10% - 100%		2% - 100%
		Discount rate	13.4	%	12.2% - 13.1%
Earnout payments (Dutch DNA acquisition) (1)	Discounted cash flow	Projected years of payments	2025-2028		2025-2028
		Discount rate	10.3	%	12.0	%

(1) For FGen and Altar acquisitions, see Note 3. In July 2021, the Company acquired Dutch DNA Biotech B.V. (“Dutch DNA”) and is obligated to make contingent earnout payments up to a maximum of $20.0 million, payable upon the achievement of certain technical and commercial milestones by Dutch DNA, as outlined in a Technical Development Agreement executed between the Company and Dutch DNA prior to the close of the acquisition.

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation

The following table provides a reconciliation of notes receivable measured at fair value using Level 3 significant unobservable inputs (in thousands):

	2023		2022
Balance at January 1,	$	7,660	$	11,559
Additions	2,653		7,660
Additions from note exchanges and amendments	13,939		—
Proceeds from notes receivable	—		(10,404)
Settlements	(7,707)		—
Change in fair value	(2,416)		705
Write-off	—		(1,860)
Balance at December 31,	$	14,129	$	7,660

The following table provides a reconciliation of the Private Placement Warrants measured at fair value using Level 3 significant unobservable inputs (in thousands):

	2023		2022
Balance at January 1,	$	3,860	$	58,558
Transfer to Level 2	—		(125)
Change in fair value	(2,014)		(54,573)
Balance at December 31,	$	1,846	$	3,860

The following table provides a reconciliation of the contingent consideration liability measured at fair value using Level 3 significant unobservable inputs (in thousands):

	2023		2022
Balance at January 1	$	24,473	$	8,467
Additions	1,397		19,912
Change in fair value	9,168		(1,262)
Settlements and payments	(10,765)		(2,644)
Balance at December 31,	$	24,273	$	24,473