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 |
|---|---|---|---|---|
| Loews Corporation | 55% | 49 | +11.3% | -2.5% |
| Markel Group | 53.6% | 63 | +11.2% | -2.6% |
| Berkshire Hathaway | 27% | 49 | +12.6% | -1.3% |
| Graham Holdings | 20.9% | 49 | +11.8% | -2% |
| Cincinnati Financial | 17.9% | 53 | +6.9% | -6.9% |
| Hingham Institution for Savings | 13.5% | 79 | +17.3% | +3.5% |
| White Mountains Insurance Group | 7.6% | 52 | +30.4% | +16.6% |
| W.R. Berkley | 2.9% | 49 | +2.3% | -11.5% |
| Nvidia | 0.8% | 49 | +99.7% | +85.9% |
| Alphabet | 0.1% | 56 | +17.6% | +3.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.