MARKETABLE INVESTMENT SECURITIES

9 Months Ended

Sep. 30, 2023

Investments, Debt and Equity Securities [Abstract]

The following table presents our Marketable investment securities:


	As of
	September 30, 2023		December 31, 2022
Marketable investment securities:
Available-for-sale debt securities:
Corporate bonds	$	175,444	$	160,559
Commercial paper	518,641		687,927
Other debt securities	66,072		17,695
Total available-for-sale debt securities	760,157		866,181
Equity securities	142,590		118,790
Total marketable investment securities, including restricted amounts	902,747		984,971
Less: Restricted marketable investment securities	(8,003)		(11,056)
Total marketable investment securities	$	894,744	$	973,915

Debt Securities

Available-for-Sale

The following table presents the components of our available-for-sale debt securities:


	Amortized		Unrealized				Estimated
	Cost		Gains		Losses		Fair Value
As of September 30, 2023
Corporate bonds	$	173,714	$	1,830	$	(100)	$	175,444
Commercial paper	518,641		—		—		518,641
Other debt securities	66,083		—		(11)		66,072
Total available-for-sale debt securities	$	758,438	$	1,830	$	(111)	$	760,157
As of December 31, 2022
Corporate bonds	$	160,494	$	125	$	(60)	$	160,559
Commercial paper	687,956		—		(29)		687,927
Other debt securities	17,785		—		(90)		17,695
Total available-for-sale debt securities	$	866,235	$	125	$	(179)	$	866,181

The following table presents the activity on our available-for-sale debt securities:


	For the three months ended September 30,				For the nine months ended September 30,
	2023		2022		2023		2022
Proceeds from sales	$	71,586	$	—	$	209,063	$	37,904

As of September 30, 2023, we have $752.4 million of available-for-sale debt securities with contractual maturities of one year or less and $7.8 million with contractual maturities greater than one year.

Equity Securities

The following table presents the activity of our equity securities:


	For the three months ended September 30,				For the nine months ended September 30,
	2023		2022		2023		2022
Proceeds from sales	$	1,430	$	34,121	$	3,457	$	34,374
Gains (losses) on investments, net	$	13,637	$	18,273	$	816	$	26,536

Fair Value Measurements

The following table presents our marketable investment securities categorized by the fair value hierarchy, certain of which have historically experienced volatility:


	Level 1		Level 2		Total
As of September 30, 2023
Cash equivalents (including restricted)	$	536	$	984,843	$	985,379
Available-for-sale debt securities:
Corporate bonds	$	—	$	175,444	$	175,444
Commercial paper	—		518,641		518,641
Other debt securities	61,212		4,860		66,072
Total available-for-sale debt securities	61,212		698,945		760,157
Equity securities	133,968		8,622		142,590
Total marketable investment securities, including restricted amounts	195,180		707,567		902,747
Less: Restricted marketable investment securities	(8,003)		—		(8,003)
Total marketable investment securities	$	187,177	$	707,567	$	894,744

As of December 31, 2022
Cash equivalents (including restricted)	$	657	$	595,814	$	596,471
Available-for-sale debt securities:
Corporate bonds	$	—	$	160,559	$	160,559
Commercial paper	—		687,927		687,927
Other debt securities	15,968		1,727		17,695
Total available-for-sale debt securities	15,968		850,213		866,181
Equity securities	109,002		9,788		118,790
Total marketable investment securities, including restricted amounts	124,970		860,001		984,971
Less: Restricted marketable investment securities	(11,056)		—		(11,056)
Total marketable investment securities	$	113,914	$	860,001	$	973,915

As of September 30, 2023 and December 31, 2022, we did not have any investments that were categorized within Level 3 of the fair value hierarchy.