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% | 13 | +7.7% | +8.3% |
| Loews Corporation | 54.1% | 90 | -0.5% | -2.4% |
| Berkshire Hathaway | 25.1% | 90 | +6.2% | +4.4% |
| Graham Holdings | 21.9% | 90 | +4.4% | +2.6% |
| Hingham Institution for Savings | 21.7% | 23 | +8.9% | +9.5% |
| Cincinnati Financial | 19.4% | 9 | +6.8% | +7.4% |
| White Mountains Insurance Group | 7.9% | 92 | +11.6% | +9.8% |
| W.R. Berkley | 3.7% | 90 | +3.7% | +1.9% |
| Alphabet | 2.3% | 6 | -7.4% | -6.8% |
| Nvidia | 0.9% | 90 | -38.4% | -40.2% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.