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% | 70 | -0.7% | -4.4% |
| Loews Corporation | 54.4% | 56 | -3.5% | -7.3% |
| Berkshire Hathaway | 28.2% | 56 | +3.9% | +0.1% |
| Graham Holdings | 21.7% | 56 | +0.4% | -3.3% |
| Hingham Institution for Savings | 21.6% | 80 | +2.6% | -1.2% |
| Cincinnati Financial | 21.4% | 64 | +4.6% | +0.8% |
| White Mountains Insurance Group | 7.2% | 58 | -7% | -10.8% |
| W.R. Berkley | 4% | 56 | +6.1% | +2.3% |
| Alphabet | 2.2% | 63 | -6.4% | -10.1% |
| Nvidia | 1% | 56 | -16% | -19.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.