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 | 58.9% | 42 | +0.1% | -1.4% |
| Loews Corporation | 54.5% | 28 | -2% | -3.5% |
| Berkshire Hathaway | 28.7% | 28 | +4.7% | +3.3% |
| Graham Holdings | 22.1% | 28 | -1.9% | -3.3% |
| Cincinnati Financial | 20.4% | 36 | +2.3% | +0.9% |
| Hingham Institution for Savings | 19.9% | 52 | +0.5% | -1% |
| White Mountains Insurance Group | 7.4% | 30 | -3.1% | -4.6% |
| W.R. Berkley | 4.1% | 28 | +6.4% | +5% |
| Alphabet | 2.1% | 35 | -13.2% | -14.7% |
| Nvidia | 0.9% | 28 | -20.9% | -22.3% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.