Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2020

Summary of Cash and Cash Equivalents and Investments' Costs, Gross Unrealized Gains (Losses), and Fair Value by Major Security Type Recorded as Cash and Cash Equivalents or Short-Term or Long-Term Investments

The following tables present our cash and cash equivalents’ and investments’ costs, gross unrealized gains (losses), and fair value by major security type recorded as cash and cash equivalents or short-term or long-term investments as of September 30, 2020 and December 31, 2019 (in thousands):


	As of September 30, 2020
	Cost		Net Unrealized Gains		Fair Value		Cash and Cash Equivalents		Short-term Investments		Long-term Investments
Cash	$	49,548	$	—	$	49,548	$	49,548	$	—	$	—
Level 1:
Money market funds	$	31,433	$	—	$	31,433	$	31,433	$	—	$	—
Subtotal	$	31,433	$	—	$	31,433	$	31,433	$	—	$	—
Level 2:
Commercial paper	$	116,849	$	22	$	116,871	$	14,971	$	101,900	$	—
Certificates of deposit	2,800		—		2,800		—		2,800		—
U.S. Treasury and agency bonds	592,734		1,723		594,457		—		393,501		200,956
Corporate bonds	186,738		641		187,379		—		129,058		58,321
Subtotal	$	899,121	$	2,386	$	901,507	$	14,971	$	627,259	$	259,277
Level 3:	$	—	$	—	$	—	$	—	$	—	$	—
Total	$	980,102	$	2,386	$	982,488	$	95,952	$	627,259	$	259,277

	As of December 31, 2019
	Cost		Net Unrealized Gains (Losses)		Fair Value		Cash and Cash Equivalents		Short-term Investments		Long-term Investments
Cash	$	53,039	$	—	$	53,039	$	53,039	$	—	$	—
Level 1:
Money market funds	$	223,580	$	—	$	223,580	$	223,580	$	—	$	—
Subtotal	$	223,580	$	—	$	223,580	$	223,580	$	—	$	—
Level 2:
Commercial paper	$	217,140	$	(6)	$	217,134	$	98,325	$	118,809	$	—
Certificates of deposit	1,000		—		1,000		—		—		1,000
U.S. Treasury and agency bonds	294,953		199		295,152		35,005		161,767		98,380
Corporate bonds	184,516		444		184,960		—		96,419		88,541
Subtotal	$	697,609	$	637	$	698,246	$	133,330	$	376,995	$	187,921
Level 3:	$	—	$	—	$	—	$	—	$	—	$	—
Total	$	974,228	$	637	$	974,865	$	409,949	$	376,995	$	187,921