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 | 58.5% | 48 | -0.3% | -1.2% |
| Loews Corporation | 55.3% | 34 | -0.8% | -1.7% |
| Berkshire Hathaway | 27.9% | 34 | +4.4% | +3.5% |
| Graham Holdings | 22.6% | 34 | +0.4% | -0.5% |
| Hingham Institution for Savings | 20.6% | 58 | +1.5% | +0.6% |
| Cincinnati Financial | 20.3% | 42 | +2.4% | +1.5% |
| White Mountains Insurance Group | 7.2% | 36 | -6.5% | -7.4% |
| W.R. Berkley | 4% | 34 | +4.3% | +3.4% |
| Alphabet | 2.1% | 41 | -11.8% | -12.7% |
| Nvidia | 1% | 34 | -20.9% | -21.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.