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 | 55.5% | 54 | +12.6% | -1.5% |
| Markel Group | 53.8% | 68 | +11.1% | -3% |
| Berkshire Hathaway | 27.4% | 54 | +13.4% | -0.7% |
| Graham Holdings | 21.5% | 54 | +11.9% | -2.2% |
| Cincinnati Financial | 18.2% | 58 | +7.4% | -6.7% |
| Hingham Institution for Savings | 14.5% | 84 | +16.6% | +2.5% |
| White Mountains Insurance Group | 7.7% | 57 | +31.9% | +17.8% |
| W.R. Berkley | 3% | 54 | +4% | -10.1% |
| Nvidia | 0.7% | 54 | +87.3% | +73.2% |
| Alphabet | 0.1% | 61 | +12.8% | -1.3% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.