Cash and Investments in Marketable Securities

9 Months Ended

Sep. 30, 2022

Fair Value Disclosures [Abstract]

Cash and Investments in Marketable Securities

Cash and Investments in Marketable Securities

Cash and investments in marketable securities, including cash equivalents, are as follows (in thousands):

	Estimated Fair Value at
	September 30, 2022		December 31, 2021
Cash and cash equivalents	$	105,758	$	25,218
Short-term investments	440,629		708,737
Long-term investments	—		64,828
Total cash and investments in marketable securities	$	546,387	$	798,783

We invest in liquid, high quality debt securities which are subject to interest rate risk. To minimize the exposure due to an adverse shift in interest rates, we invest in securities with maturities of two years or less and maintain a weighted average maturity of one year or less. As of December 31, 2021, all of our long-term investments had maturities between one and two years.

Our portfolio of cash and investments in marketable securities includes (in thousands):

	Fair Value Hierarchy Level	September 30, 2022								December 31, 2021
		Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Value		Fair Value
Corporate notes and bonds	2	$	115,652	$	—	$	(1,489)	$	114,163	$	278,121
Corporate commercial paper	2	358,066		—		(1,763)		356,303		478,629
Obligations of U.S. government agencies	2	1,130		—		—		1,130		5,875
Available-for-sale investments		$	474,848	$	—	$	(3,252)	$	471,596	$	762,625
Money market funds	1							50,696		23,968
Certificates of deposit	2							15,754		10,940
Cash	N/A							8,341		1,250
Total cash and investments in marketable securities								$	546,387	$	798,783

For the three and nine months ended September 30, 2022 and 2021, there were no transfers between Level 1 and Level 2 of the fair value hierarchy. At December 31, 2021, our gross unrealized losses totaled $0.7 million, and our gross unrealized gains were insignificant.