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 | 59.5% | 71 | -0.2% | -4.6% |
| Loews Corporation | 54.3% | 57 | -4.5% | -8.9% |
| Berkshire Hathaway | 28% | 57 | +3.9% | -0.5% |
| Graham Holdings | 22% | 57 | +1.1% | -3.3% |
| Hingham Institution for Savings | 22% | 81 | +3.7% | -0.7% |
| Cincinnati Financial | 21.7% | 65 | +4.8% | +0.4% |
| White Mountains Insurance Group | 7% | 59 | -9.4% | -13.8% |
| W.R. Berkley | 4% | 57 | +5.7% | +1.4% |
| Alphabet | 2.2% | 64 | -5.3% | -9.7% |
| Nvidia | 1% | 57 | -16.1% | -20.5% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.