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Livermore
Livermore
ZHEN

White Mountains Insurance Group Ltd

WTM
Exchange
NYSE
Industry
Fire, Marine & Casualty Insurance
SEC CIK
0000776867

No open-market purchases or sales by White Mountains Insurance Group Ltd insiders were filed in the last 90 days; 356 institutions reported holding it in 13F filings for Q2 2026, worth $4.57B in total; Southeastern Asset Management (Longleaf) is the only superinvestor holding it.

13F holders, Q1 2026

Institutional positions in White Mountains Insurance Group Ltd as of Mar 31, 2026. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works

Institutional holders
368
+23 vs. Q4 2025
Shares held
2.21M
+232.8K (+11.8%) vs. Q4 2025
Total value
$4.86B
+$748.7M (+18.2%) vs. Q4 2025
New holders
49
120 more added
Sold out
26
111 more reduced

8 institutions that held it in Q4 2025 haven't filed for Q1 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.

Compare with Q4 2025: new holders, sold out and not filed yet

Holders and value by quarter

Institutions reporting WTM on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.

Institutional holdersQ1 2026: 368 institutions
Q1 2021: 245 institutionsQ2 2021: 233 institutionsQ3 2021: 232 institutionsQ4 2021: 243 institutionsQ1 2022: 244 institutionsQ2 2022: 259 institutionsQ3 2022: 251 institutionsQ4 2022: 265 institutionsQ1 2023: 262 institutionsQ2 2023: 258 institutionsQ3 2023: 272 institutionsQ4 2023: 295 institutionsQ1 2024: 303 institutionsQ2 2024: 306 institutionsQ3 2024: 304 institutionsQ4 2024: 325 institutionsQ1 2025: 322 institutionsQ2 2025: 325 institutionsQ3 2025: 338 institutionsQ4 2025: 353 institutionsQ1 2026: 368 institutionsQ2 2026: 356 institutions
Value heldQ1 2026: $4.86B
Q1 2021: $3.02BQ2 2021: $3.11BQ3 2021: $2.86BQ4 2021: $2.71BQ1 2022: $3.09BQ2 2022: $3.32BQ3 2022: $2.98BQ4 2022: $3.20BQ1 2023: $3.09BQ2 2023: $3.13BQ3 2023: $3.40BQ4 2023: $3.42BQ1 2024: $4.06BQ2 2024: $4.14BQ3 2024: $3.78BQ4 2024: $4.43BQ1 2025: $4.44BQ2 2025: $4.17BQ3 2025: $3.89BQ4 2025: $4.67BQ1 2026: $4.86BQ2 2026: $4.57B
Institutions holding WTM and their total value by quarter
QuarterHoldersValue
Q2 2026356$4.57B
Q1 2026368$4.86B
Q4 2025353$4.67B
Q3 2025338$3.89B
Q2 2025325$4.17B
Q1 2025322$4.44B
Q4 2024325$4.43B
Q3 2024304$3.78B
Q2 2024306$4.14B
Q1 2024303$4.06B
Q4 2023295$3.42B
Q3 2023272$3.40B
Q2 2023258$3.13B
Q1 2023262$3.09B
Q4 2022265$3.20B
Q3 2022251$2.98B
Q2 2022259$3.32B
Q1 2022244$3.09B
Q4 2021243$2.71B
Q3 2021232$2.86B
Q2 2021233$3.11B
Q1 2021245$3.02B

Institutions, Q1 2026

Shares, value and share of portfolio for each institution holding White Mountains Insurance Group Ltd; share changes are against Q4 2025.

Institutions holding WTM in Q1 2026
InstitutionSharesValue% of portfolioChange in sharesAction
Quent Capital, LLC42$92.3K0.01%−18−30.0%Reduced
MetLife Investment Management41$90.1K0.00%00.0%Unchanged
Northwestern Mutual Wealth Management Co40$87.9K0.00%+31+344.4%Added
Valley National Advisers Inc40$87.0K0.01%00.0%Unchanged
BNP PARIBAS ASSET MANAGEMENT Holding S.A.39$85.7K0.00%+7+21.9%Added
Basecamp Wealth Advisors LLC38$83.5K0.02%+4+11.8%Added
Advisory Services Network, LLC37$81.3K0.00%+37New
WPG Advisers, LLC30$65.9K0.05%−2−6.3%Reduced
Tower Research Capital LLC (TRC)25$54.9K0.00%+6+31.6%Added
Nomura Asset Management Co Ltd22$48.3K0.00%00.0%Unchanged
Fifth Third Bancorp21$46.1K0.00%−4−16.0%Reduced
Keating Financial Advisory Services, Inc.21$46.1K0.01%00.0%Unchanged
Opal Wealth Advisors, LLC20$43.9K0.01%+20New
Fortitude Family Office, LLC20$43.9K0.01%00.0%Unchanged
Reyes Financial Architecture, Inc.20$43.9K0.04%+20New
Bessemer Group Inc19$42.0K0.00%−7−26.9%Reduced
CX Institutional19$42.0K0.00%+19New
Delta Asset Management LLC19$41.7K0.00%00.0%Unchanged
LRI Investments, LLC17$37.3K0.00%−62−78.5%Reduced
Ancora Advisors, LLC16$35.2K0.00%+2+14.3%Added
Jones Financial Companies LLLP16$34.5K0.00%+1+6.7%Added
Gables Capital Management Inc.15$33.0K0.01%00.0%Unchanged
Global Assets Advisory, LLC15$33.0K0.01%+15New
Smartleaf Asset Management LLC15$32.9K0.00%+1+7.1%Added
Private Trust Co NA14$30.8K0.00%−1−6.7%Reduced
Quantbot Technologies LP13$28.6K0.00%−21−61.8%Reduced
Miller Global Investments, LLC12$26.4K0.02%00.0%Unchanged
Los Angeles Capital Management LLC12$26.4K0.00%00.0%Unchanged
Capital Advisors, Ltd. LLC12$26.0K0.00%00.0%Unchanged
TD Private Client Wealth LLC11$24.2K0.00%−7−38.9%Reduced
EverSource Wealth Advisors, LLC11$24.2K0.00%+1+10.0%Added
SJS Investment Consulting Inc.10$22.0K0.00%+1+11.1%Added
Mitsubishi UFJ Kokusai Asset Management Co., Ltd.9$19.8K0.00%00.0%Unchanged
BFSG, LLC9$19.8K0.00%+1+12.5%Added
Huntington National Bank8$17.6K0.00%−6−42.9%Reduced
Bell Investment Advisors, Inc8$17.6K0.00%00.0%Unchanged
Rothschild Investment LLC8$17.6K0.00%+7+700.0%Added
Hillsdale Investment Management Inc.8$17.6K0.00%+8New
Bartlett & Co. Wealth Management LLC8$17.3K0.00%00.0%Unchanged
CoreFirst Bank & Trust7$15.4K0.01%00.0%Unchanged
Private Wealth Asset Management, LLC7$15.4K0.00%00.0%Unchanged
JFS Wealth Advisors, LLC6$13.2K0.00%00.0%Unchanged
1620 Investment Advisors, Inc.6$13.2K0.01%00.0%Unchanged
Pinnacle Wealth Planning Services, Inc.6$13.2K0.00%+2+50.0%Added
Mather Group, LLC.5$11.0K0.00%+5New
Covestor Ltd4$9.00K0.01%−93−95.9%Reduced
Clearstead Advisors, LLC4$8.79K0.00%−33−89.2%Reduced
Root Financial Partners, LLC4$8.79K0.00%−4−50.0%Reduced
MV Capital Management, Inc.4$8.79K0.00%00.0%Unchanged
Parkside Financial Bank & Trust3$6.59K0.00%−59−95.2%Reduced
Crewe Advisors LLC3$6.59K0.00%00.0%Unchanged
South State Corp.3$6.59K0.00%00.0%Unchanged
Marquette Asset Management, LLC3$6.59K0.00%+1+50.0%Added
Larson Financial Group LLC3$6.59K0.00%+3New
Twin Peaks Wealth Advisors, LLC3$6.59K0.00%+3New
Whipplewood Advisors, LLC3$6.59K0.00%+3New
TD Capital Management LLC2$4.40K0.00%00.0%Unchanged
Private Wealth Management Group, LLC2$4.39K0.00%00.0%Unchanged
Assetmark, Inc2$4.39K0.00%00.0%Unchanged
CVA Family Office, LLC2$4.39K0.00%+2New
True Wealth Design, LLC2$4.39K0.00%+2New
Kilter Group LLC1$2.20K0.00%00.0%Unchanged
Financial Network Wealth Advisors LLC1$2.20K0.00%00.0%Unchanged
First Horizon Corp1$2.20K0.00%+1New
SHP Wealth Management1$2.20K0.00%+1New
ZRC Wealth Management, LLC1$2.20K0.00%+1New
Bare Financial Services, Inc1$2.20K0.00%+1New
Burk Holdings LLC1$2.20K0.00%+1New
Forum Financial Management, LP0$00.00%−2,016−100.0%Sold out
Holocene Advisors, LP0$00.00%−998−100.0%Sold out
Squarepoint Ops LLC0$00.00%−706−100.0%Sold out
Jump Financial, LLC0$00.00%−658−100.0%Sold out
King Luther Capital Management Corp0$00.00%−560−100.0%Sold out
Oak Thistle LLC0$00.00%−530−100.0%Sold out
Lecap Asset Management Ltd0$00.00%−340−100.0%Sold out
Greenland Capital Management LP0$00.00%−290−100.0%Sold out
Highlander Partners, L.P.0$00.00%−280−100.0%Sold out
Envestnet Portfolio Solutions, Inc.0$00.00%−261−100.0%Sold out
Cambridge Investment Research Advisors, Inc.0$00.00%−200−100.0%Sold out
Two Sigma Securities, LLC0$00.00%−160−100.0%Sold out
Crossmark Global Holdings, Inc.0$00.00%−137−100.0%Sold out
AlphaGrep UK Ltd0$00.00%−129−100.0%Sold out
Swiss Life Asset Management Ltd0$00.00%−117−100.0%Sold out
Johnson Investment Counsel Inc0$00.00%−115−100.0%Sold out
Jefferies Financial Group Inc.0$00.00%−112−100.0%Sold out
Childress Capital Advisors, LLC0$00.00%−99−100.0%Sold out
Callan Family Office, LLC0$00.00%−97−100.0%Sold out
Caitong International Asset Management Co., Ltd0$00.00%−61−100.0%Sold out
Quarry LP0$00.00%−26−100.0%Sold out
Danske Bank A/S0$00.00%−20−100.0%Sold out
Torren Management, LLC0$00.00%−13−100.0%Sold out
SageView Advisory Group, LLC0$00.00%−4−100.0%Sold out
Quattro Advisors LLC0$00.00%−2−100.0%Sold out
Bruce G. Allen Investments, LLC0$00.00%−1−100.0%Sold out
Vanguard Group Inc––––Not filed
Norges Bank––––Not filed
Brandywine Global Investment Management, LLC––––Not filed
Prospector Partners LLC––––Not filed
Global Retirement Partners, LLC––––Not filed
David Loasby––––Not filed