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 | 54.8% | 62 | +10.1% | -3.7% |
| Loews Corporation | 54.5% | 48 | +8.1% | -5.7% |
| Berkshire Hathaway | 26.8% | 48 | +9.9% | -3.9% |
| Graham Holdings | 21% | 48 | +11% | -2.8% |
| Cincinnati Financial | 18.1% | 52 | +5.8% | -8% |
| Hingham Institution for Savings | 13.4% | 78 | +15.8% | +2% |
| White Mountains Insurance Group | 7.8% | 51 | +26.8% | +13% |
| W.R. Berkley | 2.9% | 48 | +1.6% | -12.2% |
| Nvidia | 0.8% | 48 | +111.3% | +97.5% |
| Alphabet | 0.1% | 55 | +18.3% | +4.5% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.