Investment Securities

12 Months Ended

Dec. 31, 2023

Investments, Debt and Equity Securities [Abstract]

Investment securities consisted of the following (in thousands):


	December 31, 2023
	Amortized Cost		Unrealized Gains		Unrealized (Losses)		Estimated Fair Value
U.S. Government Agency Securities	$	150,651	$	148	$	(204)	$	150,595
FDIC Certificates of Deposit	4,410		2		(12)		4,400
Certificates of Deposit	60,000		—		—		60,000
Commercial Paper	78,610		59		(27)		78,642
Corporate Notes/Bonds	118,899		281		(143)		119,037
	$	412,570	$	490	$	(386)	$	412,674


	December 31, 2022
	Amortized Cost		Unrealized Gains		Unrealized (Losses)		Estimated Fair Value
U.S. Government Agency Securities	$	188,465	$	14	$	(1,729)	$	186,750
FDIC Certificates of Deposit	4,155		3		(72)		4,086
Certificates of Deposit	7,500		—		—		7,500
Commercial Paper	100,711		3		(269)		100,445
Corporate Notes/Bonds	189,588		1		(2,141)		187,448
	$	490,419	$	21	$	(4,211)	$	486,229

The Company has classified all of its investment securities as available-for-sale, including those with maturities beyond one year, as current assets on the consolidated balance sheets based on the highly liquid nature of the investment securities and because these investment securities are considered available for use in current operations. As of December 31, 2023 and 2022, the Company held $77.8 million and $71.5 million, respectively, of available-for-sale investment securities with contractual maturity dates more than one year and less than two years, with the remainder of the available-for-sale investment securities having contractual maturity dates less than one year.

The aggregate related fair value of investments with unrealized losses as of December 31, 2023 was $165.2 million, which consisted of $78.0 million from U.S. government agency securities, $3.7 million of certificates of deposit, $32.1 million of commercial paper, and $51.4 million of corporate notes/bonds. $70.1 million of the aggregate fair value of investments with unrealized losses as of December 31, 2023 has been held in a continuous unrealized loss position for over 12 months, with the remaining $95.1 million held in a continuous unrealized loss position for less than 12 months. As of December 31, 2023, $60.0 million of the certificates of deposit and $2.5 million of the U.S. Government Agency Securities balance are listed as cash equivalents. As of December 31, 2022, the aggregate related fair value of investments with unrealized losses was $438.3 million. $49.1 million of the aggregate fair value of investments with unrealized losses as of December 31, 2022 has been held in a continuous unrealized loss position for over than 12 months, with the remaining $389.2 million held in a continuous unrealized loss position for less than 12 months.

The Company reviewed all of the investments which were in a loss position at the respective balance sheet dates, as well as the remainder of the portfolio. The Company has analyzed the unrealized losses and determined that market conditions were the primary factor driving these changes. After analyzing the securities in an unrealized loss position, the portion of these losses that relate to changes in credit quality is insignificant. The Company does not intend to sell these securities, nor is it more likely than not that the Company will be required to sell them prior to the end of their contractual terms. Furthermore, the Company does not believe that these securities expose the Company to undue market risk or counterparty credit risk.