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 | 58.7% | 74 | +0.2% | -4.1% |
| Loews Corporation | 54.3% | 60 | -3.6% | -7.9% |
| Berkshire Hathaway | 28.1% | 60 | +5% | +0.7% |
| Graham Holdings | 22.1% | 60 | +1.5% | -2.8% |
| Hingham Institution for Savings | 21.8% | 84 | +4.4% | +0.1% |
| Cincinnati Financial | 21.5% | 68 | +5.1% | +0.8% |
| White Mountains Insurance Group | 6.9% | 62 | -9.6% | -13.9% |
| W.R. Berkley | 3.9% | 60 | +6.1% | +1.7% |
| Alphabet | 2.2% | 67 | -4.9% | -9.2% |
| Nvidia | 0.9% | 60 | -17.7% | -22.1% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.