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 |
|---|---|---|---|---|
| Loews Corporation | 55.7% | 53 | +12.4% | -2.2% |
| Markel Group | 54% | 67 | +11.9% | -2.8% |
| Berkshire Hathaway | 27.3% | 53 | +13.2% | -1.4% |
| Graham Holdings | 21% | 53 | +12.4% | -2.2% |
| Cincinnati Financial | 18.2% | 57 | +7.5% | -7.1% |
| Hingham Institution for Savings | 14.2% | 83 | +17.5% | +2.9% |
| White Mountains Insurance Group | 7.9% | 56 | +34.1% | +19.4% |
| W.R. Berkley | 2.9% | 53 | +2% | -12.6% |
| Nvidia | 0.8% | 53 | +103.7% | +89% |
| Alphabet | 0.1% | 60 | +16.5% | +1.9% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.