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 | 58.8% | 47 | +0.5% | -0.9% |
| Loews Corporation | 55.5% | 33 | -0.1% | -1.5% |
| Berkshire Hathaway | 28.5% | 33 | +6% | +4.7% |
| Graham Holdings | 22.1% | 33 | +0.2% | -1.1% |
| Hingham Institution for Savings | 20.4% | 57 | +2.2% | +0.8% |
| Cincinnati Financial | 20.3% | 41 | +3% | +1.6% |
| White Mountains Insurance Group | 7.4% | 35 | -4.5% | -5.8% |
| W.R. Berkley | 4% | 33 | +5.8% | +4.4% |
| Alphabet | 2% | 40 | -15.9% | -17.2% |
| Nvidia | 0.9% | 33 | -24.2% | -25.6% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.