Tom Gayner’s CoStar Group CSGP Stock Holding History

Tom Gayner’s Portfolio CSGP Stock Details CSGP Fund Activity

Bought

Maintained

Sold

Quarter	Market Value	Status	Shares	Change in Stake	Trade Value	Portfolio Weight	Portfolio Position
2025 Q3	–	Sell	-18,600	Closed	-$1.5M	–	133
2025 Q2	$1.5M	Hold	18,600	–	–	0.01%	134
2025 Q1	$1.47M	Hold	18,600	–	–	0.01%	129
2024 Q4	$1.33M	Hold	18,600	–	–	0.01%	125
2024 Q3	$1.4M	Hold	18,600	–	–	0.01%	126
2024 Q2	$1.38M	Hold	18,600	–	–	0.01%	130
2024 Q1	$1.8M	Hold	18,600	–	–	0.02%	127
2023 Q4	$1.63M	Hold	18,600	–	–	0.02%	123
2023 Q3	$1.43M	Hold	18,600	–	–	0.02%	126
2023 Q2	$1.66M	Hold	18,600	–	–	0.02%	124
2023 Q1	$1.28M	Hold	18,600	–	–	0.02%	127
2022 Q4	$1.44M	Hold	18,600	–	–	0.02%	125
2022 Q3	$1.3M	Hold	18,600	–	–	0.02%	122
2022 Q2	$1.12M	Buy	18,600 +1,000	+6%	+$60.6K	0.02%	123
2022 Q1	$1.17M	Buy	17,600 +14,500	+468%	+$963K	0.01%	117
2021 Q4	$245K	Buy	+3,100	New	+$260K	﹤0.01%	119

Other funds holding CSGP

Vanguard Group Malvern, Pennsylvania $6.9T AUM 27.45% 1-Year Est. Return

BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return

BAMCO Inc New York $66.6B AUM 7.35% 1-Year Est. Return

Principal Financial Group Des Moines, Iowa $204B AUM 27.99% 1-Year Est. Return

State Street Boston, Massachusetts $3.37T AUM 44.26% 1-Year Est. Return

Geode Capital Management Boston, Massachusetts $1.88T AUM 44.46% 1-Year Est. Return

ACM

AKRE Capital Management Middleburg, Virginia $5.12B AUM 19.08% 1-Year Est. Return

Morgan Stanley New York $1.89T AUM 35.08% 1-Year Est. Return

Baillie Gifford & Co Edinburgh, United Kingdom $110B AUM 4.8% 1-Year Est. Return

Massachusetts Financial Services Boston, Massachusetts $315B AUM 27.84% 1-Year Est. Return

Tom Gayner's CSGP Position: Q3 2025 in Review

Tom Gayner sold out of CoStar Group (CSGP) in Q3 2025, closing a stake of 18,600 shares — an estimated $1.5M sold.

Tom Gayner first reported a position in CSGP in Q4 2021 and held it in 15 quarters. The position peaked at $1.8M in Q1 2024. 905 funds tracked by Wall St. Rank hold CSGP as of Q3 2025.

Tom Gayner reported no remaining CoStar Group position as of Q3 2025 after selling out during the quarter.
Tom Gayner sold 18,600 CoStar Group shares in Q3 2025, an estimated $1.5M.
Tom Gayner first reported a position in CoStar Group in Q4 2021 and held it in 15 quarters.
Tom Gayner's CoStar Group position peaked at $1.8M in Q1 2024.
905 funds tracked by Wall St. Rank held CoStar Group as of Q3 2025.

Based on Markel Group's 13F filing for Q3 2025, filed 31 Oct 2025.