Equity Securities

6 Months Ended

Jun. 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)	June 30, 2025		December 31, 2024
Marketable equity securities	$	396.0	$	386.8
Non-marketable equity securities		218.3		202.4
Equity method investments		101.1		102.1
	$	715.4	$	691.3

Investments in marketable equity securities are summarized as follows:


(in millions)	Cost		Unrealized (losses) gains			Estimated fair value
June 30, 2025
Common stocks	$	393.7	$	(9.5	)	$	384.2
Preferred stocks		11.4		0.4			11.8
	$	405.1	$	(9.1	)	$	396.0
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 $26.1 million and $19.1 million resulting from changes in the fair values of marketable equity securities were recognized for the three and six months ended June 30, 2025, respectively, which included net unrealized gains of $26.0 million and $19.3 million on securities still held at June 30, 2025, respectively. Net losses of $12.2 million and $1.3 million resulting from changes in the fair values of marketable equity securities were recognized for the three and six months ended June 30, 2024, respectively, which included net unrealized losses of $13.2 million and $2.7 million on securities still held at June 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 six months ended June 30, 2025 and 2024, is as follows:


	Three Months Ended June 30,					Six Months Ended June 30,
(in millions)	2025		2024			2025			2024
Carrying amount, beginning of period	$	216.6	$	226.1		$	202.4		$	224.1
Net additions		0.2		1.3			15.2			3.1
Gross unrealized gains		1.5		1.2			1.5			1.4
Gross unrealized losses and impairments		—		(2.8	)		(0.8	)		(2.8	)
Carrying amount, end of period	$	218.3	$	225.8		$	218.3		$	225.8

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


(in millions)	June 30, 2025		December 31, 2024
Cumulative gross unrealized gains	$	246.3	$	244.8
Cumulative gross unrealized losses and impairments	$	352.4	$	351.6