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Equibles

WTM

White Mountains Insurance Group Ltd

Company with tickers: WTM

CIK
776867
CUSIP
G9618E107
Shares Outstanding
2,476,670
13F Activity (30d)
14 filings 10 filers

Institutional ownership from SEC Form 13F filings. Investment managers with more than $100 million in U.S. equities must disclose their positions every quarter, within 45 days of quarter-end, so the holdings shown can lag the market by up to a quarter.

Holders: 357
Total Value: $4,327,327,681
Total Shares: 1,969,689
Showing 1–100 of 357 holdings by value · page 1 of 4

Institutional Ownership Trend

25 quarters

Superinvestors Holding WTM

All superinvestors →
Joel Greenblatt $19,875,897 Ray Dalio $909,541

Holder Concentration

Across 357 13F filers · Δ vs Dec 31, 2025
Top Holder
8.0%
Jun 2023 → Mar 2026 · range 8.0% – 11.3%
−2.5 pts
Top 5
31.5%
Jun 2023 → Mar 2026 · range 31.5% – 39.5%
−2.1 pts
Top 10
51.0%
Jun 2023 → Mar 2026 · range 51.0% – 59.8%
−3.3 pts
HHI
337
Jun 2023 → Mar 2026 · range 337 – 458
Broadly held−53

Quarterly Activity

vs Dec 31, 2025
New
42
Increased
120
Decreased
108
Sold Out
36
Unchanged
87
Holder count: +6
Institutional value: -7.4%
Shares held: -12.4%

Top Buyers

vs Dec 31, 2025
Institution Added Now Holds Open
Mega JANE STREET GROUP, LLC +12,101 13,808
Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP +10,833 10,965
Mega GOLDMAN SACHS GROUP INC +10,523 15,783
Mega AMERICAN CENTURY COMPANIES INC +7,413 8,308
Mid GENDELL JEFFREY L +5,294 37,814

Top Sellers

vs Dec 31, 2025
Institution Sold Now Holds Open
Mega MORGAN STANLEY −22,856 59,295
Large Boston Partners −19,452 57,459
Mid SOUTHEASTERN ASSET MANAGEMENT INC/TN/ −12,788 18,864
Large Select Equity Group, L.P. −9,153 10,560
Mid REINHART PARTNERS, LLC. −6,599 37,374

Top New Positions

vs Dec 31, 2025
Institution Acquired Value (USD) Open
Small Boussard & Gavaudan Investment Management LLP 13,975 $30,702,516
Large Empowered Funds, LLC 1,284 $2,820,895
Small DIVERSIFIED MANAGEMENT INC 1,158 $2,544,079
Mid Capula Management Ltd 921 $2,023,400
Small Fieldview Capital Management, LLC 729 $1,601,583

Top Sold-Out Positions

vs Dec 31, 2025
Institution Previously Held Last Value (USD) Open
Mega VANGUARD GROUP INC 235,698 $489,787,513
Mega NORGES BANK 32,184 $66,879,317
Large Brandywine Global Investment Management, LLC 3,226 $6,703,724
Small Forum Financial Management, LP 2,016 $4,189,308
Large Holocene Advisors, LP 998 $2,073,873
Filter: New 42 Increased 120 Reduced 108 Sold out 36 Unchanged 87
Showing 100 of 357
All Common Calls Puts
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Holder Value (USD) % of 13F Shares Open
Mega DIMENSIONAL FUND ADVISORS LP $344,083,480 7.95% 156,618
Mega NEUBERGER BERMAN GROUP LLC $273,993,865 6.33% 124,715
Mid River Road Asset Management, LLC $264,775,422 6.12% 120,519
Mega BlackRock, Inc. $248,977,076 5.75% 113,328
Mid COOKE & BIELER LP $230,366,634 5.32% 104,857
Large FULLER & THALER ASSET MANAGEMENT, INC. $229,716,334 5.31% 104,561
Mid FIDUCIARY MANAGEMENT INC /WI/ $186,886,599 4.32% 85,066
Small Wallace Capital Management Inc. $173,109,463 4.00% 78,795
Mega MORGAN STANLEY $130,268,736 3.01% 59,295
Large Boston Partners $126,235,122 2.92% 57,459
Large LONDON CO OF VIRGINIA $125,514,521 2.90% 57,131
Mega STATE STREET CORP $107,998,159 2.50% 49,158
Mega GEODE CAPITAL MANAGEMENT, LLC $92,533,757 2.14% 42,119
Mega T. Rowe Price Investment Management, Inc. $91,202,400 2.11% 41,513
Mid GENDELL JEFFREY L $83,075,845 1.92% 37,814
Mid REINHART PARTNERS, LLC. $82,109,183 1.90% 37,374
Large LORD, ABBETT & CO. LLC $72,741,345 1.68% 33,110
Mega BANK OF AMERICA CORP /DE/ Bank $62,301,389 1.44% 28,358
Mid Cannell & Spears LLC $61,574,197 1.42% 28,027
Mega CHARLES SCHWAB INVESTMENT MANAGEMENT INC $53,256,507 1.23% 24,241
Mega RAYMOND JAMES FINANCIAL INC $52,619,386 1.22% 23,951
Small Mraz, Amerine & Associates, Inc. $48,726,375 1.13% 22,179
Mid SOUTHEASTERN ASSET MANAGEMENT INC/TN/ $41,443,452 0.96% 18,864
Large Allspring Global Investments Holdings, LLC $40,889,819 0.94% 18,612
Large BROWN ADVISORY INC $39,202,553 0.91% 17,844
Mega GOLDMAN SACHS GROUP INC $34,674,618 0.80% 15,783
Mega ENVESTNET ASSET MANAGEMENT INC $34,191,288 0.79% 15,563
Mega NORTHERN TRUST CORP Bank $34,041,893 0.79% 15,495
Mega WELLINGTON MANAGEMENT GROUP LLP $32,699,550 0.76% 14,884
Small Boussard & Gavaudan Investment Management LLP $30,702,516 0.71% 13,975
Mega JANE STREET GROUP, LLC $30,335,622 0.70% 13,808
Mid HORIZON KINETICS ASSET MANAGEMENT LLC $28,806,539 0.67% 13,112
Small ELKHORN PARTNERS LIMITED PARTNERSHIP $27,901,392 0.64% 12,700
Mega VICTORY CAPITAL MANAGEMENT INC $24,485,119 0.57% 11,145
Large SEI INVESTMENTS CO $24,381,861 0.56% 11,098
Mega SUSQUEHANNA INTERNATIONAL GROUP, LLP $24,089,666 0.56% 10,965
Large Select Equity Group, L.P. $23,199,897 0.54% 10,560
Mega UBS Group AG $22,938,458 0.53% 10,441
Large Quantinno Capital Management LP $21,495,056 0.50% 9,784
Small SPEECE THORSON CAPITAL GROUP INC $20,644,833 0.48% 9,397
Large Gotham Asset Management, LLC $19,875,897 0.46% 9,047
Mega D. E. Shaw & Co., Inc. $19,574,913 0.45% 8,910
Mega WELLS FARGO & COMPANY/MN $19,293,701 0.45% 8,782
Mega Bank of New York Mellon Corp Bank $18,551,124 0.43% 8,444
Mega AMERICAN CENTURY COMPANIES INC $18,252,343 0.42% 8,308
Large GW&K Investment Management, LLC $17,413,104 0.40% 7,926
Mega UBS AM, a distinct business unit of UBS ASSET MANAGEMENT AMERICAS LLC $17,193,404 0.40% 7,826
Mega AQR CAPITAL MANAGEMENT LLC $17,000,072 0.39% 7,738
Small Triad Investment Management $16,756,213 0.39% 7,627
Mid THOMPSON SIEGEL & WALMSLEY LLC $15,837,884 0.37% 7,209
Mega BNP PARIBAS ARBITRAGE, SA $14,550,466 0.34% 6,623
Mid ROYCE & ASSOCIATES LP $14,192,361 0.33% 6,460
Mega California Public Employees Retirement System Pension $14,091,301 0.33% 6,414
Large HOTCHKIS & WILEY CAPITAL MANAGEMENT LLC $13,287,214 0.31% 6,048
Large WCM INVESTMENT MANAGEMENT, LLC $13,170,775 0.30% 5,995
Mid Williams Jones Wealth Management, LLC. $11,411,010 0.26% 5,194
Mega Swiss National Bank Bank $11,063,890 0.26% 5,036
Mega FRANKLIN RESOURCES INC $10,541,012 0.24% 4,798
Mega Nuveen, LLC $9,466,699 0.22% 4,309
Small Phocas Financial Corp. $9,429,352 0.22% 4,292
Mega RHUMBLINE ADVISERS $9,077,838 0.21% 4,132
Large Creative Planning $8,895,491 0.21% 4,049
Large MARSHALL WACE, LLP $8,519,810 0.20% 3,878
Mid LEE DANNER & BASS INC $7,036,862 0.16% 3,203
Mid Edgestream Partners, L.P. $6,876,484 0.16% 3,130
Mega FIRST TRUST ADVISORS LP $6,718,303 0.16% 3,058
Mega Invesco Ltd. $6,518,377 0.15% 2,967
Large CALIFORNIA STATE TEACHERS RETIREMENT SYSTEM Pension $6,342,623 0.15% 2,887
Mega AMERIPRISE FINANCIAL INC $6,296,486 0.15% 2,866
Large RENAISSANCE TECHNOLOGIES LLC $5,736,262 0.13% 2,611
Mega CITADEL ADVISORS LLC $5,718,686 0.13% 2,603
Mega JPMORGAN CHASE & CO $5,639,592 0.13% 2,567
Large NEW YORK STATE COMMON RETIREMENT FUND Pension $5,520,960 0.13% 2,513
Large MML INVESTORS SERVICES, LLC $5,402,324 0.12% 2,459
Mega Legal & General Group Plc $5,290,278 0.12% 2,408
Large HRT FINANCIAL LP $5,217,780 0.12% 2,375
Large STATE BOARD OF ADMINISTRATION OF FLORIDA RETIREMENT SYSTEM Pension $4,967,326 0.11% 2,261
Mid DARK FOREST CAPITAL MANAGEMENT LP $4,954,144 0.11% 2,255
Mega PRICE T ROWE ASSOCIATES INC /MD/ $4,857,478 0.11% 2,211
Large Robeco Institutional Asset Management B.V. $4,787,175 0.11% 2,179
Large DAVENPORT & Co LLC $4,664,146 0.11% 2,123
Mid BRADLEY FOSTER & SARGENT INC/CT $4,398,313 0.10% 2,002
Mega ARROWSTREET CAPITAL, LIMITED PARTNERSHIP $4,202,784 0.10% 1,913
Mid PARSONS CAPITAL MANAGEMENT INC/RI $4,147,860 0.10% 1,888
Large Cerity Partners LLC $4,101,722 0.09% 1,867
Mid Atlantic Union Bankshares Corp $3,877,634 0.09% 1,765
Large AGF MANAGEMENT LTD $3,741,422 0.09% 1,703
Small Regency Capital Management Inc.\DE $3,372,333 0.08% 1,535
Mid OPPENHEIMER ASSET MANAGEMENT INC. $3,251,500 0.08% 1,480
Large HighTower Advisors, LLC $3,179,001 0.07% 1,447
Mega CITIGROUP INC $3,075,743 0.07% 1,400
Large Corient Private Wealth LLC $3,071,350 0.07% 1,398
Mega LPL Financial LLC $3,064,759 0.07% 1,395
Large Tidal Investments LLC $2,961,502 0.07% 1,348
Large STIFEL FINANCIAL CORP $2,842,865 0.07% 1,294
Large Empowered Funds, LLC $2,820,895 0.07% 1,284
Large CAPTRUST FINANCIAL ADVISORS $2,713,245 0.06% 1,235
Mid Quadrature Capital Ltd $2,664,912 0.06% 1,213
Mega ROYAL BANK OF CANADA Bank $2,625,366 0.06% 1,195
Small 1834 INVESTMENT ADVISORS CO $2,583,624 0.06% 1,176

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