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 | 56.2% | 43 | +8.7% | -4.3% |
| Loews Corporation | 52.5% | 29 | -1.4% | -14.4% |
| Berkshire Hathaway | 27.1% | 29 | +8.7% | -4.3% |
| Cincinnati Financial | 21.2% | 33 | +11.6% | -1.4% |
| Graham Holdings | 20.4% | 29 | +8.3% | -4.8% |
| Hingham Institution for Savings | 13.7% | 59 | +10.3% | -2.7% |
| White Mountains Insurance Group | 6.7% | 32 | +7.5% | -5.6% |
| W.R. Berkley | 3.1% | 29 | +4.5% | -8.5% |
| Nvidia | 0.8% | 29 | +114.6% | +101.6% |
| Alphabet | 0.1% | 36 | +17% | +3.9% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.