HoldcoTracker marks the reported 13-F equity portfolios of operating and holding companies to last close. Institutional investors with over $100 million in U.S. equities file 13-Fs disclosing those holdings within 45 days of each quarter-end; the lead column below sizes each filer's equity book against the parent company's market cap.
| Company | 13-F as % of Mkt Cap | Days Since Filing | Since Filing | vs S&P since filing |
|---|---|---|---|---|
| Markel Group | 60.2% | 22 | +2.9% | +0.4% |
| Loews Corporation | 55.8% | 8 | +1.1% | -1.5% |
| Berkshire Hathaway | 29.5% | 8 | +5.3% | +2.7% |
| Graham Holdings | 21.5% | 8 | -1.9% | -4.4% |
| Hingham Institution for Savings | 21.1% | 32 | +2.8% | +0.3% |
| Cincinnati Financial | 20.9% | 16 | +3.9% | +1.3% |
| White Mountains Insurance Group | 7.8% | 10 | +2.8% | +0.2% |
| W.R. Berkley | 4.1% | 8 | +4.9% | +2.3% |
| Alphabet | 1.9% | 15 | -19.1% | -21.7% |
| Nvidia | 0.9% | 8 | -26.8% | -29.3% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.