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 | 56.9% | 39 | +8% | -5.3% |
| Loews Corporation | 51.6% | 25 | -4.8% | -18.2% |
| Berkshire Hathaway | 27% | 25 | +7.8% | -5.4% |
| Cincinnati Financial | 21.9% | 29 | +11.4% | -2% |
| Graham Holdings | 20.8% | 25 | +8.6% | -4.8% |
| Hingham Institution for Savings | 13.7% | 55 | +10.8% | -2.6% |
| White Mountains Insurance Group | 6.6% | 28 | +5.5% | -7.9% |
| W.R. Berkley | 3.2% | 25 | +5% | -8.5% |
| Nvidia | 0.7% | 25 | +101.9% | +88.5% |
| Alphabet | 0.1% | 32 | +19% | +5.6% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.