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 |
|---|---|---|---|---|
| Loews Corporation | 54% | 46 | +6.6% | -6.5% |
| Markel Group | 53% | 60 | +8.7% | -4.5% |
| Berkshire Hathaway | 26.6% | 46 | +8% | -5.1% |
| Graham Holdings | 21.1% | 46 | +9.7% | -3.4% |
| Cincinnati Financial | 18.1% | 50 | +4.8% | -8.3% |
| Hingham Institution for Savings | 13.4% | 76 | +12.7% | -0.5% |
| White Mountains Insurance Group | 7.5% | 49 | +24.2% | +11% |
| W.R. Berkley | 2.9% | 46 | +1.3% | -11.9% |
| Nvidia | 0.9% | 46 | +120.4% | +107.2% |
| Alphabet | 0.1% | 53 | +17.2% | +4% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.