The following table sets forth our financial assets as of December 31, 2022 and 2021 that are measured at fair value on a recurring basis during the period:


	December 31, 2022
	Cost or Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Total Estimated Fair Value

	(in thousands)
Cash	$	1,325,946	$	—	$	—	$	1,325,946
Level 1 securities:
U.S. government securities	1,630,224		109		(9,484)		1,620,849
U.S. government agency securities	175,269		19		(188)		175,100
Publicly traded equity securities (1)	102,189		20,859		(31,548)		91,500
Level 2 securities:
Corporate debt securities	309,942		32		(1,462)		308,512
Commercial paper	290,589		—		—		290,589
Certificates of deposit	157,965		—		(1)		157,964
Total	$	3,992,124	$	21,019	$	(42,683)	$	3,970,460


(1)			During the year ended December 31, 2022, we reclassified strategic investments from Level 3 to Level 1 at their fair value using the beginning-of-period approach, following the commencement of public market trading of the investments during the quarter (a portion of which was subject to short-term lock-up restrictions as of December 31, 2022).