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 | 58.7% | 36 | +2.2% | -0.9% |
| Loews Corporation | 55.5% | 22 | +0.1% | -3% |
| Berkshire Hathaway | 28.8% | 22 | +5% | +1.9% |
| Graham Holdings | 22.3% | 22 | -1.1% | -4.3% |
| Cincinnati Financial | 20.4% | 30 | +3.2% | +0.1% |
| Hingham Institution for Savings | 20.3% | 46 | +2.5% | -0.7% |
| White Mountains Insurance Group | 7.5% | 24 | -1% | -4.2% |
| W.R. Berkley | 4.2% | 22 | +7.1% | +3.9% |
| Alphabet | 2.1% | 29 | -13.2% | -16.3% |
| Nvidia | 0.9% | 22 | -22.8% | -25.9% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.