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 | 56.5% | 70 | +13.4% | +0.7% |
| Markel Group | 52.7% | 84 | +8.3% | -4.4% |
| Berkshire Hathaway | 28.1% | 70 | +13.2% | +0.6% |
| Graham Holdings | 20.4% | 70 | +5.3% | -7.4% |
| Cincinnati Financial | 19.4% | 74 | +8.6% | -4.1% |
| Hingham Institution for Savings | 15% | 3 | -3.2% | -2.2% |
| White Mountains Insurance Group | 7.5% | 73 | +28% | +15.3% |
| W.R. Berkley | 3% | 70 | +6.5% | -6.1% |
| Nvidia | 0.6% | 70 | +71.4% | +58.7% |
| Alphabet | 0.1% | 77 | +2% | -10.7% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.