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% | 46 | +1.2% | -0.6% |
| Loews Corporation | 55.1% | 32 | -0.7% | -2.5% |
| Berkshire Hathaway | 28.6% | 32 | +6.3% | +4.5% |
| Graham Holdings | 22% | 32 | +0.5% | -1.3% |
| Cincinnati Financial | 20.3% | 40 | +3.3% | +1.5% |
| Hingham Institution for Savings | 20.2% | 56 | +2.5% | +0.7% |
| White Mountains Insurance Group | 7.5% | 34 | -3.6% | -5.4% |
| W.R. Berkley | 4.1% | 32 | +6.2% | +4.4% |
| Alphabet | 2% | 39 | -13.3% | -15.1% |
| Nvidia | 1% | 32 | -23.1% | -25% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.