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 | 57.2% | 64 | +13.6% | +0.2% |
| Markel Group | 51.6% | 78 | +6.8% | -6.6% |
| Berkshire Hathaway | 28.8% | 64 | +16% | +2.6% |
| Graham Holdings | 20.4% | 64 | +8.3% | -5.1% |
| Cincinnati Financial | 14.4% | 68 | -18.9% | -32.3% |
| Hingham Institution for Savings | 14.1% | 94 | +14.4% | +0.9% |
| White Mountains Insurance Group | 7.7% | 67 | +34.2% | +20.8% |
| W.R. Berkley | 3% | 64 | +4.9% | -8.6% |
| Nvidia | 0.6% | 64 | +62.1% | +48.7% |
| Alphabet | 0.1% | 71 | +1.3% | -12.1% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.