XT
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XTX Topco’s White Mountains Insurance WTM Stock Holding History

XTX Topco’s Portfolio WTM Stock Details WTM Fund Activity
Bought
Maintained
Sold
Quarter Market Value Status Shares Change in
Stake 		Trade Value Portfolio Weight Portfolio Position
2026
Q2 		$3.41M Buy
1,644
+1,394
+558% +$2.98M 0.04% 636
2026
Q1 		$549K Buy
250
+21
+9% +$45K 0.01% 1964
2025
Q4 		$476K Buy
+229
New +$448K 0.01% 1647
2025
Q1 		– Sell
-517
Closed -$1.01M – 3201
2024
Q4 		$1.01M Buy
517
+117
+29% +$221K 0.08% 299
2024
Q3 		$678K Buy
+400
New +$697K 0.05% 617
2024
Q1 		– Sell
-252
Closed -$379K – 2385
2023
Q4 		$379K Buy
+252
New +$375K 0.08% 439
2023
Q3 		– Sell
-212
Closed -$294K – 2063
2023
Q2 		$294K Buy
+212
New +$298K 0.05% 739
2021
Q2 		– Sell
-227
Closed -$253K – 1130
2021
Q1 		$253K Buy
+227
New +$254K 0.12% 376

Other funds holding WTM

Dimensional Fund Advisors
Dimensional Fund Advisors Austin, Texas $552B AUM 44.19% 1-Year Est. Return
Neuberger Berman Group
Neuberger Berman Group New York $150B AUM 40.08% 1-Year Est. Return
BlackRock
BlackRock New York $6.73T AUM 46.02% 1-Year Est. Return
RRAM
River Road Asset Management Louisville, Kentucky $8.99B AUM 12.83% 1-Year Est. Return
Vanguard Portfolio Management
Vanguard Portfolio Management Malvern, Pennsylvania $2.22T AUM
Vanguard Capital Management
Vanguard Capital Management Malvern, Pennsylvania $4.68T AUM
Fuller & Thaler Asset Management
Fuller & Thaler Asset Management San Mateo, California $36.7B AUM 74.15% 1-Year Est. Return
CB
Cooke & Bieler Philadelphia, Pennsylvania $8.65B AUM 9.66% 1-Year Est. Return
WCM
Wallace Capital Management Dallas, Texas $912M AUM 21.45% 1-Year Est. Return
FMI
Fiduciary Management Inc Milwaukee, Wisconsin $7.03B AUM 11.68% 1-Year Est. Return

XTX Topco's WTM Position: Q2 2026 in Review

XTX Topco increased its White Mountains Insurance (WTM) stake by 558% in Q2 2026, buying an estimated $2.98M and bringing the position to 1,644 shares worth $3.41M. The position accounts for 0.04% of the portfolio, ranked #636.

XTX Topco first reported a position in WTM in Q1 2021 and has held it in 8 quarters since. 356 funds tracked by Wall St. Rank hold WTM as of Q2 2026.

  • XTX Topco held 1,644 shares of White Mountains Insurance worth $3.41M as of Q2 2026.
  • XTX Topco bought 1,394 White Mountains Insurance shares in Q2 2026, an estimated $2.98M.
  • White Mountains Insurance made up 0.04% of XTX Topco's portfolio in Q2 2026, its #636 holding.
  • XTX Topco first reported a position in White Mountains Insurance in Q1 2021 and has held it in 8 quarters since.
  • 356 funds tracked by Wall St. Rank held White Mountains Insurance as of Q2 2026.

Based on XTX Topco's 13F filing for Q2 2026, filed 14 Aug 2026.