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 | 60.1% | 69 | -1.1% | -5.4% |
| Loews Corporation | 54.4% | 55 | -5.2% | -9.5% |
| Berkshire Hathaway | 28.1% | 55 | +2.5% | -1.7% |
| Graham Holdings | 21.8% | 55 | -0.1% | -4.4% |
| Hingham Institution for Savings | 21.8% | 79 | +2.1% | -2.2% |
| Cincinnati Financial | 21.8% | 63 | +4.1% | -0.2% |
| White Mountains Insurance Group | 7% | 57 | -11.4% | -15.7% |
| W.R. Berkley | 4.1% | 55 | +6.8% | +2.5% |
| Alphabet | 2.3% | 62 | -2.4% | -6.6% |
| Nvidia | 1% | 55 | -11.5% | -15.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.