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 | 55.9% | 53 | +8.9% | -4.7% |
| Loews Corporation | 53.2% | 39 | -0.1% | -13.8% |
| Berkshire Hathaway | 27% | 39 | +8.1% | -5.5% |
| Graham Holdings | 20.9% | 39 | +7.3% | -6.3% |
| Cincinnati Financial | 20.6% | 43 | +10.9% | -2.7% |
| Hingham Institution for Savings | 14% | 69 | +9.1% | -4.5% |
| White Mountains Insurance Group | 7.1% | 42 | +11.8% | -1.8% |
| W.R. Berkley | 3.2% | 39 | +4.5% | -9.2% |
| Nvidia | 0.9% | 39 | +138.5% | +124.9% |
| Alphabet | 0.1% | 46 | +13.1% | -0.6% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.