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 | 56.9% | 40 | +7.1% | -5.5% |
| Loews Corporation | 51.5% | 26 | -5.2% | -17.8% |
| Berkshire Hathaway | 26.9% | 26 | +7.5% | -5.1% |
| Cincinnati Financial | 22% | 30 | +11.1% | -1.5% |
| Graham Holdings | 21.1% | 26 | +7.8% | -4.8% |
| Hingham Institution for Savings | 13.8% | 56 | +9.8% | -2.8% |
| White Mountains Insurance Group | 6.6% | 29 | +5.7% | -6.9% |
| W.R. Berkley | 3.2% | 26 | +5.2% | -7.4% |
| Nvidia | 0.7% | 26 | +99.3% | +86.7% |
| Alphabet | 0.1% | 33 | +17.4% | +4.7% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.