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 | 58.2% | 6 | +4.1% | +0.9% |
| Loews Corporation | 56.7% | 83 | +14% | -3.5% |
| Berkshire Hathaway | 26.9% | 83 | +14.5% | -3% |
| Graham Holdings | 21.2% | 83 | +12.8% | -4.7% |
| Hingham Institution for Savings | 21.1% | 16 | +4.9% | +1.7% |
| Cincinnati Financial | 20.2% | 87 | +11.7% | -5.8% |
| White Mountains Insurance Group | 7.6% | 86 | +25.9% | +8.4% |
| W.R. Berkley | 2.9% | 83 | +3.2% | -14.2% |
| Nvidia | 0.6% | 83 | +75.8% | +58.4% |
| Alphabet | 0.1% | 90 | +7.8% | -9.7% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.