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 | 56.7% | 1 | +1.6% | +1.6% |
| Loews Corporation | 56.6% | 78 | +14.1% | +0.2% |
| Berkshire Hathaway | 27.2% | 78 | +14.3% | +0.4% |
| Graham Holdings | 20.5% | 78 | +11.2% | -2.7% |
| Cincinnati Financial | 19.7% | 82 | +9.3% | -4.6% |
| Hingham Institution for Savings | 15.7% | 11 | +3.2% | +3.1% |
| White Mountains Insurance Group | 7.5% | 81 | +24.5% | +10.6% |
| W.R. Berkley | 2.9% | 78 | +4.7% | -9.2% |
| Nvidia | 0.6% | 78 | +54.8% | +40.9% |
| Alphabet | 0.1% | 85 | +0.4% | -13.5% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.