Marketable Securities

3 Months Ended

Mar. 31, 2024

Investments, Debt and Equity Securities [Abstract]

Marketable securities as of March 31, 2024 and December 31, 2023 consist of both available-for-sale debt securities of investment grade issuers (see below and Note 6) as well as equity securities of publicly traded companies (see Note 6).

The following tables summarize the Company's investments in available-for-sale debt securities:


(In millions)	Amortized		Unrealized				Fair
As of March 31, 2024	Cost Basis		Gains		Losses		Value
Corporate bonds	$	7,478.9	$	6.1	$	(83.9)	$	7,401.1
U.S. government and government agency obligations	5,291.2		0.4		(18.2)		5,273.4
Sovereign bonds	59.8		—		(0.8)		59.0
Commercial paper	867.1		0.3		(0.5)		866.9
Certificates of deposit	389.7		0.2		—		389.9
Asset-backed securities	126.0		—		(1.3)		124.7
	$	14,212.7	$	7.0	$	(104.7)	$	14,115.0

As of December 31, 2023
Corporate bonds	$	6,492.5	$	10.4	$	(104.9)	$	6,398.0
U.S. government and government agency obligations	4,839.6		2.4		(8.6)		4,833.4
Sovereign bonds	58.1		—		(0.9)		57.2
Commercial paper	636.8		0.2		(0.2)		636.8
Certificates of deposit	520.8		0.6		—		521.4
Asset-backed securities	88.2		0.1		(1.2)		87.1
	$	12,636.0	$	13.7	$	(115.8)	$	12,533.9

The Company classifies its investments in available-for-sale debt securities based on their contractual maturity dates. The available-for-sale debt securities as of March 31, 2024 mature at various dates through June 2029. The fair values of available-for-sale debt securities by contractual maturity consist of the following:


	March 31,		December 31,
(In millions)	2024		2023
Maturities within one year	$	7,917.5	$	8,114.8
Maturities after one year through five years	6,184.1		4,414.5
Maturities after five years	13.4		4.6
	$	14,115.0	$	12,533.9

The following table shows the fair value of the Company's available-for-sale debt securities that have unrealized losses, aggregated by investment category and length of time that the individual securities have been in a continuous loss position.


	Less than 12 Months				12 Months or Greater				Total
(In millions) As of March 31, 2024	Fair Value		Unrealized Loss		Fair Value		Unrealized Loss		Fair Value		Unrealized Loss
Corporate bonds	$	4,490.4	$	(10.7)	$	2,910.7	$	(73.2)	$	7,401.1	$	(83.9)
U.S. government and government agency obligations	5,220.4		(15.9)		53.0		(2.3)		5,273.4		(18.2)
Sovereign bonds	32.5		(0.2)		26.5		(0.6)		59.0		(0.8)
Commercial paper	866.9		(0.5)		—		—		866.9		(0.5)
Asset-backed securities	99.2		(0.6)		25.5		(0.7)		124.7		(1.3)
	$	10,709.4	$	(27.9)	$	3,015.7	$	(76.8)	$	13,725.1	$	(104.7)

As of December 31, 2023
Corporate bonds	$	2,363.3	$	(2.4)	$	4,034.7	$	(102.5)	$	6,398.0	$	(104.9)
U.S. government and government agency obligations	4,780.6		(6.0)		52.7		(2.6)		4,833.3		(8.6)
Sovereign bonds	12.4		(0.1)		44.8		(0.8)		57.2		(0.9)
Commercial paper	636.8		(0.2)		—		—		636.8		(0.2)
Asset-backed securities	61.8		(0.3)		25.3		(0.9)		87.1		(1.2)
	$	7,854.9	$	(9.0)	$	4,157.5	$	(106.8)	$	12,012.4	$	(115.8)

The unrealized losses on corporate bonds as of March 31, 2024 were primarily driven by increased interest rates. The Company has reviewed its portfolio of available-for-sale debt securities and determined that the decline in fair value below cost did not result from credit-related factors. In addition, the Company does not intend to sell, and it is not more likely than not that the Company will be required to sell, such securities before recovery of their amortized cost bases.

With respect to marketable securities, for the three months ended March 31, 2024 and 2023, amounts reclassified from Accumulated other comprehensive loss into Other (expense) income, net were related to realized gains/losses on sales of available-for-sale debt securities. For the three months ended March 31, 2024 and 2023, realized gains/losses on sales of marketable securities were not material