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 | 59.1% | 50 | 0% | -2.3% |
| Loews Corporation | 55.8% | 36 | -0.9% | -3.1% |
| Berkshire Hathaway | 28.5% | 36 | +4.6% | +2.4% |
| Graham Holdings | 22.4% | 36 | -0.1% | -2.3% |
| Cincinnati Financial | 20.6% | 44 | +3.1% | +0.9% |
| Hingham Institution for Savings | 20.4% | 60 | +1.7% | -0.6% |
| White Mountains Insurance Group | 7.1% | 38 | -8.6% | -10.8% |
| W.R. Berkley | 4.1% | 36 | +5.9% | +3.7% |
| Alphabet | 2.1% | 43 | -10.7% | -12.9% |
| Nvidia | 1% | 36 | -17.6% | -19.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.