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 | 59.7% | 18 | +2.4% | -1.1% |
| Loews Corporation | 55.6% | 4 | +3% | -0.5% |
| Berkshire Hathaway | 29% | 4 | +4.3% | +0.8% |
| Graham Holdings | 21.7% | 4 | -1.2% | -4.7% |
| Hingham Institution for Savings | 20.6% | 28 | +1.9% | -1.6% |
| Cincinnati Financial | 20.6% | 12 | +4% | +0.5% |
| White Mountains Insurance Group | 7.7% | 6 | +2% | -1.5% |
| W.R. Berkley | 4.1% | 4 | +5.4% | +1.9% |
| Alphabet | 2% | 11 | -13.9% | -17.4% |
| Nvidia | 1% | 4 | -18% | -21.5% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.