Marketable Securities

9 Months Ended

Sep. 30, 2025

Investments, Debt and Equity Securities [Abstract]

Marketable securities as of September 30, 2025 and December 31, 2024 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 September 30, 2025	Cost Basis		Gains		Losses		Value
Corporate bonds	$	9,624.3	$	78.8	$	(5.4)	$	9,697.7
U.S. government and government agency obligations	4,691.7		12.1		(0.5)		4,703.3
Commercial paper	445.1		0.2		—		445.3
Certificates of deposit	310.2		0.2		—		310.4
Asset-backed securities	293.8		1.4		—		295.2
Sovereign bonds	69.8		0.5		(0.1)		70.2
	$	15,434.9	$	93.2	$	(6.0)	$	15,522.1

As of December 31, 2024
Corporate bonds	$	8,226.9	$	25.1	$	(31.4)	$	8,220.6
U.S. government and government agency obligations	4,820.5		3.4		(6.9)		4,817.0
Commercial paper	548.3		0.4		—		548.7
Certificates of deposit	380.6		0.5		—		381.1
Asset-backed securities	279.0		0.6		(0.3)		279.3
Sovereign bonds	82.7		0.1		(0.4)		82.4
	$	14,338.0	$	30.1	$	(39.0)	$	14,329.1

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 September 30, 2025 mature at various dates through February 2038. The fair values of available-for-sale debt securities by contractual maturity consist of the following:


	September 30,		December 31,
(In millions)	2025		2024
Maturities within one year	$	5,937.2	$	6,524.3
Maturities after one year through five years	9,518.9		7,804.8
Maturities after five years	66.0		—
	$	15,522.1	$	14,329.1

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


	Less than 12 Months				12 Months or Greater				Total
(In millions) As of September 30, 2025	Fair Value		Unrealized Losses		Fair Value		Unrealized Losses		Fair Value		Unrealized Losses
Corporate bonds	$	9,300.3	$	(1.5)	$	397.4	$	(3.9)	$	9,697.7	$	(5.4)
U.S. government and government agency obligations	4,541.8		(0.4)		161.5		(0.1)		4,703.3		(0.5)
Sovereign bonds	56.0		(0.1)		14.2		—		70.2		(0.1)
	$	13,898.1	$	(2.0)	$	573.1	$	(4.0)	$	14,471.2	$	(6.0)

As of December 31, 2024
Corporate bonds	$	7,175.8	$	(14.2)	$	1,044.8	$	(17.2)	$	8,220.6	$	(31.4)
U.S. government and government agency obligations	4,675.3		(6.2)		141.7		(0.7)		4,817.0		(6.9)
Asset-backed securities	265.4		(0.3)		13.9		—		279.3		(0.3)
Sovereign bonds	63.3		(0.3)		19.1		(0.1)		82.4		(0.4)
	$	12,179.8	$	(21.0)	$	1,219.5	$	(18.0)	$	13,399.3	$	(39.0)

Amounts reclassified from Accumulated other comprehensive income (loss) into Other income (expense), net, related to realized gains/losses on sales of available-for-sale debt securities; such amounts were not material for the three and nine months ended September 30, 2025 and 2024.