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 | 59.5% | 63 | -2.1% | -4.6% |
| Loews Corporation | 54.7% | 49 | -5.3% | -7.7% |
| Berkshire Hathaway | 28.2% | 49 | +1.6% | -0.9% |
| Graham Holdings | 21.8% | 49 | -1.7% | -4.2% |
| Hingham Institution for Savings | 21.4% | 73 | -0.5% | -2.9% |
| Cincinnati Financial | 21.3% | 57 | +2% | -0.5% |
| White Mountains Insurance Group | 7% | 51 | -12.1% | -14.6% |
| W.R. Berkley | 4.1% | 49 | +3.6% | +1.1% |
| Alphabet | 2.1% | 56 | -13.3% | -15.8% |
| Nvidia | 1% | 49 | -13.3% | -15.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.