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% | 26 | +3.5% | +0.9% |
| Loews Corporation | 55.5% | 12 | +1.4% | -1.2% |
| Berkshire Hathaway | 29% | 12 | +5.4% | +2.8% |
| Graham Holdings | 21.5% | 12 | -0.7% | -3.3% |
| Hingham Institution for Savings | 21.1% | 36 | +4.3% | +1.7% |
| Cincinnati Financial | 20.5% | 20 | +3.9% | +1.3% |
| White Mountains Insurance Group | 7.6% | 14 | +2.4% | -0.2% |
| W.R. Berkley | 4.2% | 12 | +5% | +2.4% |
| Alphabet | 1.9% | 19 | -18.7% | -21.3% |
| Nvidia | 0.9% | 12 | -27.3% | -29.9% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.