Investment Securities

12 Months Ended

Dec. 31, 2022

Investments, Debt and Equity Securities [Abstract]

Investment Securities

3. INVESTMENT SECURITIES

The Company reports its available-for-sale investment securities at their estimated fair values. Available-for-sale investment securities consisted of the following as of December 31, 2022 and 2021 (in thousands):

	As of December 31, 2022
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Available-for-sale investment securities:
U.S. government and agency obligations	$	154,228	$	12	$	(1,510	)	$	152,730
Certificates of deposit		4,629		—		(94	)		4,535
Corporate debt securities		145,330		—		(2,336	)		142,994
Asset-backed securities		1,497		—		(3	)		1,494
Total	$	305,684	$	12	$	(3,943	)	$	301,753

	As of December 31, 2021
	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Market Value
Available-for-sale investment securities:
U.S. government and agency obligations	$	54,637	$	—	$	(180	)		54,457
Certificates of deposit		5,735		1		(4	)		5,732
Corporate debt securities		70,600		6		(204	)		70,402
Asset-backed securities		2,421		—		—			2,421
Total	$	133,393	$	7	$	(388	)	$	133,012

As of December 31, 2022 and 2021, available-for-sale investment securities by contractual maturity were as follows (in thousands):

	As of December 31, 2022				As of December 31, 2021
	Amortized Cost		Fair Market Value		Amortized Cost		Fair Market Value
Available-for-sale investment securities:
Due in one year or less	$	246,276	$	243,542	$	31,101	$	31,078
Due after one year through five years		59,408		58,211		102,292		101,934
Total	$	305,684	$	301,753	$	133,393	$	133,012

As of December 31, 2022, available-for-sale investment securities by length of time in a net loss position were as follows (in thousands):

	As of December 31, 2022
	Less Than 12 Months					More Than 12 Months					Total
	Fair Market Value		Gross Unrealized Losses			Fair Market Value		Gross Unrealized Losses			Fair Market Value		Gross Unrealized Losses
Available-for-sale investment securities:
U.S. government and agency obligations	$	95,933	$	(702	)	$	36,681	$	(808	)	$	132,614	$	(1,510	)
Certificates of deposit		2,399		(47	)		2,136		(47	)		4,535		(94	)
Corporate debt securities		96,663		(1,399	)		43,330		(937	)		139,993		(2,336	)
Asset-backed securities		1,494		(3	)		—		—			1,494		(3	)
Total	$	196,489	$	(2,151	)	$	82,147	$	(1,792	)	$	278,636	$	(3,943	)

As of December 31, 2021, there were no available-for-sale investment securities at a loss position for a period of twelve months or more. The Company reviewed its investment holdings as of December 31, 2022 and 2021 and determined that its unrealized losses were not considered to be other-than-temporary based upon (i) the financial strength of the issuing institution, (ii) intent and ability of the securities to be held to maturity and (iii) the fact that the Company is expected to recover the amortized cost of its investment holdings. As such, the Company has not recognized any impairment in its financial statements related to its available-for-sale investment securities. During the years ended December 31, 2022, 2021, and 2020, the Company recognized ($86,000), $2,000 and $26,000, respectively, of realized net gains (losses) in the accompanying statements of operations and comprehensive loss.