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 |
|---|---|---|---|---|
| Loews Corporation | 56.2% | 41 | -2.7% | -5.7% |
| Markel Group | 49.5% | 55 | -17.8% | -20.8% |
| Berkshire Hathaway | 28.2% | 41 | +3.1% | +0.1% |
| Graham Holdings | 22% | 41 | -1.2% | -4.2% |
| Cincinnati Financial | 21.4% | 49 | +2.9% | -0.1% |
| Hingham Institution for Savings | 21% | 65 | +0.4% | -2.5% |
| White Mountains Insurance Group | 6.8% | 43 | -13.2% | -16.2% |
| W.R. Berkley | 4.2% | 41 | +4.7% | +1.8% |
| Alphabet | 2.1% | 48 | -13.1% | -16% |
| Nvidia | 1% | 41 | -13.3% | -16.2% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.