The Company's investments in marketable securities are stated at fair value and are available for sale. The following table summarizes the Company's investments in marketable securities (in thousands) as of:


	March 31, 2023
	Amortized Cost Basis		Gross Unrealized Losses		Fair Value
Marketable securities (current)
U.S. Treasury notes	$	11,005	$	(61)	$	10,944
U.S. Government-sponsored enterprise securities	22,007		(54)		21,953
Total marketable securities (current)	$	33,012	$	(115)	$	32,897


	December 31, 2022
	Amortized Cost Basis		Gross Unrealized Losses		Fair Value
Marketable securities (current)
U.S. Treasury notes	$	56,418	$	(344)	$	56,074
U.S. Government-sponsored enterprise securities	112,030		(696)		111,334
Total marketable securities (current)	$	168,448	$	(1,040)	$	167,408

The cost of securities sold is based upon the specific identification method. Interest receivable related to the marketable securities of $0.2 million was included within "Prepaid expenses and other current assets" on the Consolidated Balance Sheets as of March 31, 2023.

Interest income from marketable securities totaled $0.6 million and $1.6 million for the three months ended March 31, 2023 and 2022, respectively, and is included in "Investment income" in the Consolidated Statements of Operations.