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 | 59.1% | 19 | +2.2% | -0.6% |
| Loews Corporation | 55.9% | 5 | +3.7% | +0.9% |
| Berkshire Hathaway | 29% | 5 | +5.3% | +2.5% |
| Graham Holdings | 21.6% | 5 | -0.7% | -3.5% |
| Cincinnati Financial | 20.5% | 13 | +4% | +1.2% |
| Hingham Institution for Savings | 20.3% | 29 | +2.7% | -0.1% |
| White Mountains Insurance Group | 7.7% | 7 | +4% | +1.2% |
| W.R. Berkley | 4.1% | 5 | +5.7% | +2.9% |
| Alphabet | 2% | 12 | -15.6% | -18.4% |
| Nvidia | 0.9% | 5 | -22.5% | -25.3% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.