WTM
White Mountains Insurance Group, Ltd. · Financial Services · Insurance - Diversified
Momentum inputs (comparable managers):
holder breadth +10.0% ·
share flow -12.4% ·
net new positions +9.1%
— formula
Ownership fragmentation — more holders, smaller aggregate stake
All ownership figures: tracked 13F managers only, common-stock positions, reporting period Q1 2025
| Quarter | Holders | Δ | Shares | Reported value | New | Exits |
|---|---|---|---|---|---|---|
| Q2 2026 | 100 | -5 | 1.16M | $2.41B | +2 | −6 |
| Q1 2026 | 107 | 0 | 1.13M | $2.49B | +3 | −4 |
| Q4 2025 | 108 | +2 | 1.27M | $2.64B | +3 | — |
| Q3 2025 | 16 | +1 | 649.64K | $1.09B | +1 | −1 |
| Q2 2025 | 13 | -1 | 533.60K | $958.13M | +1 | −2 |
| Q1 2025 | 11 | +1 | 169.09K | $325.53M | +1 | — |
| Q4 2024 | 10 | 0 | 193.12K | $375.52M | — | — |
| Q3 2024 | 9 | -1 | 149.43K | $253.48M | — | −1 |
| Q2 2024 | 10 | — | 158.36K | $287.38M | — | — |
| # | Manager | Shares | Δ shares | Value | Their weight | Held | ||
|---|---|---|---|---|---|---|---|---|
| 1 | State Street Global Advisors ✦ (passive) | 54.94K | +0.1% | $105.81M | 0.0% | ▲ Add | 2 | SEC ↗ |
| 2 | Geode Capital Management ✦ (passive) | 42.19K | +6.2% | $81.27M | 0.0% | ▲ Add | 4 | SEC ↗ |
| 3 | Geode Capital Management ✦ (passive) | 42.19K | +6.2% | $81.27M | 0.0% | ▲ Add | 4 | SEC ↗ |
| 4 | Norges Bank ✦ (passive) | 30.97K | +1.0% | $59.64M | 0.0% | ▲ Add | 4 | SEC ↗ |
| 5 | Wellington Management ✦ | 25.44K | -49.0% | $48.99M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 6 | Wellington Management ✦ | 25.44K | -49.0% | $48.99M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 7 | Wellington Management ✦ | 25.44K | -49.0% | $48.99M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 8 | Wellington Management ✦ | 25.44K | -49.0% | $48.99M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 9 | AQR Capital Management ✦ | 8.49K | -16.2% | $16.22M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 10 | AQR Capital Management ✦ | 8.49K | -16.2% | $16.22M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 11 | AQR Capital Management ✦ | 8.49K | -16.2% | $16.22M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 12 | AQR Capital Management ✦ | 8.49K | -16.2% | $16.22M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 13 | D. E. Shaw & Co. ✦ | 2.36K | -13.3% | $4.54M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 14 | D. E. Shaw & Co. ✦ | 2.36K | -13.3% | $4.54M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 15 | T. Rowe Price ✦ | 1.67K | +6.8% | $3.22M | 0.0% | ▲ Add | 4 | SEC ↗ |
| 16 | Citadel Advisors ✦ | 1.18K | New | $2.26M | 0.0% | New | 1 | SEC ↗ |
| 17 | Millennium Management ✦ | 956 | -60.2% | $1.84M | 0.0% | ▼ Trim | 4 | SEC ↗ |
| 18 | Renaissance Technologies ✦ | 600 | 0.0% | $1.16M | 0.0% | Held | 4 | SEC ↗ |
| 19 | Two Sigma Investments ✦ | 300 | -36.2% | $577,743 | 0.0% | ▼ Trim | 4 | SEC ↗ |
“Their weight” = the position's share of that manager's reported 13F equity value — the conviction measure. ✦ = curated manager.
New buyers
| Citadel Advisors | $2.26M | 0.0% |
Exited
| No tracked exits this quarter. |
Full-market context: across ALL 13F filers (SEC structured data, Q1 2026): 363 holders, 2.21M shares, $4.62B reported. This is a different, older period than the tracked-universe figures above and the two are never mixed.
What else this security's tracked holders most often hold — shared-ownership counts, not fundamental relationships.