White Mountains Insurance Group LTD: which funds bought and sold
Institutions that bought and sold White Mountains Insurance Group shares in Q2 2026, from the holdings they reported to the SEC on Form 13F for March 31, 2026 and June 30, 2026.
Between March 31, 2026 and June 30, 2026, 129 institutions that filed 13F reports for both quarters added to or opened positions in White Mountains Insurance Group, and 186 cut or closed them. Together they sold a net 32K shares, −1.4% on what they held at the start of the quarter. Active managers and hedge funds on our list were net sellers of 31K shares (−4.2%); index fund managers were net buyers of 5,855 shares (+1.2%). 33 opened a new position and 41 sold out entirely.
Bought, Q2 2026 129 institutions, 33 of them new holders Sold, Q2 2026 186 institutions, 41 of them sold out
Net change, all compared −32K shares (−1.4%)
Net change, active managers −31K shares (−4.2%), 18 bought, 25 sold
Buyers versus sellers
129 bought 74 186 sold
Active managers and hedge funds 18 bought · 25 sold · −31K
Index fund managers 4 bought · 6 sold · +5,855
Other institutions 107 bought · 155 sold · −6,473
Biggest buyers
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| American Century Companies Inc Active manager | +23K +274.4% | 31K | $64.5M |
| Gendell Jeffrey L | +21K +56.7% | 59K | $123M |
| Gotham Asset Management, LLC Hedge fund | +8,893 +98.3% | 18K | $37.2M |
| Qube Research & Technologies Ltd Hedge fund | +8,657 +852.1% | 9,673 | $20.1M |
| First Trust Advisors LP | +7,546 +246.8% | 11K | $22M |
| Geode Capital Management, LLC Index funds | +7,293 +17.3% | 49K | $102M |
| Reinhart Partners, Llc. | +7,106 +19.0% | 44K | $92.3M |
| UBS Group AG | +5,757 +55.1% | 16K | $33.6M |
| Arrowstreet Capital, Limited Partnership Hedge fund | +5,371 +280.8% | 7,284 | $15.1M |
| Winmill & Co. Inc | +4,800 New position | 4,800 | $10M |
| Blackrock, Inc. Index funds | +4,543 +4.0% | 118K | $244M |
| Citadel Advisors LLC Hedge fund | +4,533 +174.1% | 7,136 | $14.8M |
| HRT Financial LP | +4,385 +184.6% | 6,760 | $14M |
| Edgestream Partners, L.P. Hedge fund | +3,448 +110.2% | 6,578 | $13.6M |
| Jane Street Group, LLC | +3,418 +24.8% | 17K | $35.7M |
| Jpmorgan Chase & Co | +2,843 +110.8% | 5,410 | $11.5M |
| Quantinno Capital Management LP | +2,840 +29.0% | 13K | $26.2M |
| Dimensional Fund Advisors LP | +2,336 +1.5% | 159K | $330M |
| Lighthouse Investment Partners, LLC Hedge fund | +1,868 New position | 1,868 | $3.9M |
| Xtx Topco Ltd | +1,394 +557.6% | 1,644 | $3.4M |
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| American Century Companies Inc Active manager | +23K +274.4% | 31K | $64.5M |
| Gotham Asset Management, LLC Hedge fund | +8,893 +98.3% | 18K | $37.2M |
| Qube Research & Technologies Ltd Hedge fund | +8,657 +852.1% | 9,673 | $20.1M |
| Arrowstreet Capital, Limited Partnership Hedge fund | +5,371 +280.8% | 7,284 | $15.1M |
| Citadel Advisors LLC Hedge fund | +4,533 +174.1% | 7,136 | $14.8M |
| Edgestream Partners, L.P. Hedge fund | +3,448 +110.2% | 6,578 | $13.6M |
| Lighthouse Investment Partners, LLC Hedge fund | +1,868 New position | 1,868 | $3.9M |
| Walleye Capital LLC Hedge fund | +1,130 New position | 1,130 | $2.3M |
| Squarepoint Ops LLC Hedge fund | +905 New position | 905 | $1.9M |
| Exoduspoint Capital Management, LP Hedge fund | +832 +136.2% | 1,443 | $3M |
Biggest sellers
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| Cooke & Bieler LP Active manager | −20K −18.8% | 85K | $176M |
| Fiduciary Management Inc Active manager | −19K −21.8% | 67K | $138M |
| Morgan Stanley | −12K −21.0% | 47K | $97.2M |
| Susquehanna International Group, LLP | −11K Sold out | 0 | — |
| Select Equity Group, L.P. Active manager | −11K Sold out | 0 | — |
| Raymond James Financial Inc | −9,118 −38.1% | 15K | $30.8M |
| UBS Am, A Distinct Business Unit Of UBS Asset Management Americas LLC | −7,765 −99.2% | 61 | $126,477 |
| T. Rowe Price Investment Management, Inc. Active manager | −7,276 −17.5% | 34K | $71M |
| Neuberger Berman Group LLC Active manager | −5,574 −4.5% | 119K | $247M |
| BNP Paribas Financial Markets | −5,454 −82.3% | 1,169 | $2.4M |
| WCM Investment Management, LLC Active manager | −4,798 −80.0% | 1,197 | $2.5M |
| River Road Asset Management, LLC Active manager | −4,639 −3.8% | 116K | $240M |
| Marshall Wace, LLP Hedge fund | −3,878 Sold out | 0 | — |
| Goldman Sachs Group Inc | −3,632 −23.0% | 12K | $25.2M |
| Vanguard Portfolio Management LLC Index funds | −3,584 −3.1% | 112K | $232M |
| Bank Of America Corp | −3,330 −11.7% | 25K | $51.9M |
| London Co Of Virginia Active manager | −3,106 −5.4% | 54K | $112M |
| Sei Investments Co | −2,990 −26.9% | 8,108 | $16.8M |
| Fuller & Thaler Asset Management, Inc. | −2,669 −2.6% | 102K | $211M |
| Renaissance Technologies LLC Hedge fund | −2,611 Sold out | 0 | — |
| Institution | Change in shares | Shares June 30, 2026 | Value |
|---|---|---|---|
| Cooke & Bieler LP Active manager | −20K −18.8% | 85K | $176M |
| Fiduciary Management Inc Active manager | −19K −21.8% | 67K | $138M |
| Select Equity Group, L.P. Active manager | −11K Sold out | 0 | — |
| T. Rowe Price Investment Management, Inc. Active manager | −7,276 −17.5% | 34K | $71M |
| Neuberger Berman Group LLC Active manager | −5,574 −4.5% | 119K | $247M |
| WCM Investment Management, LLC Active manager | −4,798 −80.0% | 1,197 | $2.5M |
| River Road Asset Management, LLC Active manager | −4,639 −3.8% | 116K | $240M |
| Marshall Wace, LLP Hedge fund | −3,878 Sold out | 0 | — |
| London Co Of Virginia Active manager | −3,106 −5.4% | 54K | $112M |
| Renaissance Technologies LLC Hedge fund | −2,611 Sold out | 0 | — |
New positions
| Institution | Shares | Value June 30, 2026 |
|---|---|---|
| Winmill & Co. Inc | 4,800 | $10M |
| Lighthouse Investment Partners, LLCHedge fund | 1,868 | $3.9M |
| Walleye Capital LLCHedge fund | 1,130 | $2.3M |
| Squarepoint Ops LLCHedge fund | 905 | $1.9M |
| Vident Advisory, LLC | 635 | $1.3M |
| Worldquant Millennium Advisors LLCHedge fund | 591 | $1.2M |
| Mirabella Financial Services LLP | 495 | $1M |
| Mps Loria Financial Planners, LLC | 383 | $794,109 |
| Btg Pactual Asset Management Us LLC | 289 | $599,210 |
| Freestone Grove Partners LPHedge fund | 240 | $497,614 |
Sold out
| Institution | Shares | Value March 31, 2026 |
|---|---|---|
| Susquehanna International Group, LLP | 11K | $24.1M |
| Select Equity Group, L.P.Active manager | 11K | $23.2M |
| Marshall Wace, LLPHedge fund | 3,878 | $8.5M |
| Renaissance Technologies LLCHedge fund | 2,611 | $5.7M |
| Dark Forest Capital Management LP | 2,255 | $5M |
| Diversified Management Inc | 1,158 | $2.5M |
| Fieldview Capital Management, LLC | 729 | $1.6M |
| Mariner, LLC | 607 | $1.3M |
| Amg National Trust Bank | 571 | $1.3M |
| Entropy Technologies, LP | 470 | $1M |
Who holds the shares
- Institutions reporting
- 354
- Ten largest holders
- 48.4% of 13F-reported shares
- Index fund managers
- 22.5% of 13F-reported shares
- Active managers and hedge funds
- 32.5% of 13F-reported shares
| Type | Bought | Sold | New | Sold out | Net change in shares | Net % |
|---|---|---|---|---|---|---|
| Active managers and hedge funds | 18 | 25 | 5 | 4 | −31K | −4.2% |
| Index fund managers | 4 | 6 | 0 | 0 | +5,855 | +1.2% |
| Other institutions | 107 | 155 | 28 | 37 | −6,473 | −0.7% |
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