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% | 29 | +2.7% | -0.6% |
| Loews Corporation | 55.8% | 15 | +1% | -2.3% |
| Berkshire Hathaway | 28.8% | 15 | +4.7% | +1.4% |
| Graham Holdings | 22.1% | 15 | -1.4% | -4.7% |
| Hingham Institution for Savings | 21.1% | 39 | +3.1% | -0.2% |
| Cincinnati Financial | 20.4% | 23 | +4.3% | +0.9% |
| White Mountains Insurance Group | 7.6% | 17 | +1.4% | -1.9% |
| W.R. Berkley | 4.2% | 15 | +7.1% | +3.8% |
| Alphabet | 2% | 22 | -17% | -20.3% |
| Nvidia | 0.9% | 15 | -24.7% | -28% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.