Equity Securities

9 Months Ended

Sep. 30, 2025

Investments, Debt and Equity Securities [Abstract]

Note 4 – Equity Securities

Investments in equity securities, by accounting classification, are summarized as follows:


(in millions)	September 30, 2025		December 31, 2024
Marketable equity securities	$	407.2	$	386.8
Non-marketable equity securities		231.4		202.4
Equity method investments		103.8		102.1
	$	742.4	$	691.3

Investments in marketable equity securities are summarized as follows:


(in millions)	Cost		Unrealized gains (losses)			Estimated fair value
September 30, 2025
Common stocks	$	379.3	$	17.5		$	396.8
Preferred stocks		9.7		0.7			10.4
	$	389.0	$	18.2		$	407.2
December 31, 2024
Common stocks	$	397.3	$	(22.6	)	$	374.7
Preferred stocks		12.0		0.1			12.1
	$	409.3	$	(22.5	)	$	386.8

Net gains of $38.7 million and $57.8 million resulting from changes in the fair values of marketable equity securities were recognized for the three and nine months ended September 30, 2025, respectively, which included net unrealized gains of $35.7 million and $55.0 million on securities still held at September 30, 2025, respectively. Net gains of $19.5 million and $18.2 million resulting from changes in the fair values of marketable equity securities were recognized for the three and nine months ended September 30, 2024, respectively, which included net unrealized gains of $17.6 million and $14.9 million on securities still held at September 30, 2024, respectively.

A summary of the changes in the carrying amounts of non-marketable equity securities, which primarily relate to the Company's venture investment portfolio, for the three and nine months ended September 30, 2025 and 2024, is as follows:


	Three Months Ended September 30,						Nine Months Ended September 30,
(in millions)	2025			2024			2025			2024
Carrying amount, beginning of period	$	218.3		$	225.8		$	202.4		$	224.1
Net additions		16.0			2.4			31.2			5.5
Gross unrealized gains		1.0			0.1			2.5			1.5
Gross unrealized losses and impairments		(3.9	)		(9.2	)		(4.7	)		(12.0	)
Carrying amount, end of period	$	231.4		$	219.1		$	231.4		$	219.1

Cumulative gross unrealized gains and cumulative gross unrealized losses and impairments related to non-marketable equity securities at September 30, 2025 and December 31, 2024, are summarized as follows:


(in millions)	September 30, 2025		December 31, 2024
Cumulative gross unrealized gains	$	247.3	$	244.8
Cumulative gross unrealized losses and impairments	$	356.3	$	351.6