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 | 59.6% | 60 | -1.2% | -3.9% |
| Loews Corporation | 54.2% | 46 | -6.1% | -8.8% |
| Berkshire Hathaway | 28.4% | 46 | +3.1% | +0.4% |
| Graham Holdings | 22.2% | 46 | -1.2% | -3.9% |
| Cincinnati Financial | 21.4% | 54 | +2.7% | 0% |
| Hingham Institution for Savings | 20.8% | 70 | +0.8% | -1.9% |
| White Mountains Insurance Group | 6.8% | 48 | -14.2% | -16.9% |
| W.R. Berkley | 4.2% | 46 | +4.1% | +1.4% |
| Alphabet | 2% | 53 | -14.8% | -17.4% |
| Nvidia | 1% | 46 | -16.5% | -19.2% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.