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 | 59.4% | 40 | +1.1% | -1.5% |
| Loews Corporation | 55.2% | 26 | -1.4% | -3.9% |
| Berkshire Hathaway | 28.7% | 26 | +4.5% | +2% |
| Graham Holdings | 22.3% | 26 | -1.5% | -4.1% |
| Cincinnati Financial | 20.6% | 34 | +2.8% | +0.2% |
| Hingham Institution for Savings | 19.9% | 50 | +1.3% | -1.3% |
| White Mountains Insurance Group | 7.6% | 28 | -2.5% | -5.1% |
| W.R. Berkley | 4.1% | 26 | +6.8% | +4.3% |
| Alphabet | 2.2% | 33 | -10.1% | -12.6% |
| Nvidia | 1% | 26 | -17.5% | -20.1% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.