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 | 58.8% | 34 | +1.8% | -0.6% |
| Loews Corporation | 55.8% | 20 | +0.2% | -2.2% |
| Berkshire Hathaway | 29% | 20 | +5.8% | +3.3% |
| Graham Holdings | 22.7% | 20 | -1.1% | -3.5% |
| Hingham Institution for Savings | 21.2% | 44 | +2.3% | -0.1% |
| Cincinnati Financial | 20.4% | 28 | +3.5% | +1.1% |
| White Mountains Insurance Group | 7.6% | 22 | +0.9% | -1.6% |
| W.R. Berkley | 4.3% | 20 | +7.2% | +4.7% |
| Alphabet | 2% | 27 | -17.2% | -19.6% |
| Nvidia | 0.9% | 20 | -26.8% | -29.3% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.