FAIR VALUE MEASUREMENTS - (Tables)

6 Months Ended

Jun. 30, 2020

Fair Value Disclosures [Abstract]

Summary of Fair Value Measurements of Cash Equivalents, Available-for-Sale Marketable Securities and Free Share Asset/Liability

The fair value measurements of the Company’s cash equivalents, marketable securities and the free shares asset are identified at the following levels within the fair value hierarchy (in thousands):

	June 30, 2020
	Fair Value Measurements
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	116,393	$	116,393	$	—	$	—
Total	116,393		116,393		—		—
Marketable securities:
Commercial paper securities	90,179		—		90,179		—
Corporate debt securities	81,844		—		81,844		—
U.S. government-sponsored entity debt securities	25,387		—		25,387		—
Total	197,410		—		197,410		—
Total cash equivalents and marketable securities	$	313,803	$	116,393	$	197,410	$	—
Free shares asset	$	167	$	—	$	—	$	167

	December 31, 2019
	Fair Value Measurements
	Total		Level 1		Level 2		Level 3
Assets:
Cash equivalents:
Money market funds	$	30,496	$	30,496	$	—	$	—
Commercial paper securities	2,999		—		2,999		—
Total	33,495		30,496		2,999		—
Marketable securities:
Commercial paper securities	155,368		—		155,368		—
Corporate debt securities	95,017		—		95,017		—
U.S. government-sponsored entity debt securities	53,493		—		53,493		—
Total	303,878		—		303,878		—
Total cash equivalents and marketable securities	$	337,373	$	30,496	$	306,877	$	—
Free shares asset	$	236	$	—	$	—	$	236

Summary of Estimated Fair Value of Free Shares Valuation Assumptions

Free Shares valuation assumptions:	June 30, 2020		December 31, 2019
Sangamo Stock Price (USD)	$	8.77	$	8.68
Sangamo France Stock Price (EUR)	€	2.16	€	2.14
USD / EUR Exchange Rate	0.89		0.91
Estimated Correlation Sangamo and Sangamo France Stock Prices	100.0%		100.0%
Sangamo Stock Price (USD) Volatility Estimate	73.8%		72.5%
Sangamo France Stock Price (EUR) Volatility Estimate	73.8%		72.5%
USD / EUR Exchange Rate Volatility Estimate	6.5%		6.6%
Risk Free Rate and Cost of Debt by Expected Exercise Date	Varies		Varies