Investments

6 Months Ended

Jun. 30, 2022

Investments

Investments

4. Investments

Short-term and long-term investments by investment type consisted of the following (in thousands):

	June 30, 2022
			Gross		Gross
	Amortized		unrealized		unrealized		Fair
	cost		gains		losses		value
Short-term investments
U.S. Government Treasury Bills	$	47,371	$	—	$	(137)	$	47,234
U.S. Government Treasury Notes		47,595		—		(458)		47,137
	$	94,966	$	—	$	(595)	$	94,371
Long-term Investments
Certificates of Deposit		1,169		—		(5)		1,164
U.S. Government Treasury Notes - Maturity One - Two Years		21,971		16		(335)		21,652
	$	23,140	$	16	$	(340)	$	22,816

	December 31, 2021
			Gross		Gross
	Amortized		unrealized		unrealized		Fair
Short-term investments	cost		gains		losses		value
U.S. Government Treasury Bills	$	4,983	$	—	$	(2)	$	4,981
U.S. Government Treasury Notes		10,142		—		(13)		10,129
	$	15,125	$	—	$	(15)	$	15,110
Long-term Investments
U.S. Government Treasury Notes - Maturity One - Five Years	$	9,966	$	—	$	—	$	9,966
	$	9,966	$	—	$	—	$	9,966