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 | 58% | 76 | +19.7% | +8.5% |
| Markel Group | 52.2% | 90 | +10.2% | -1.1% |
| Berkshire Hathaway | 27.9% | 76 | +16.5% | +5.3% |
| Graham Holdings | 19.7% | 76 | +9.8% | -1.5% |
| Cincinnati Financial | 19.5% | 80 | +10.1% | -1.2% |
| Hingham Institution for Savings | 15.5% | 9 | +1.6% | +3.9% |
| White Mountains Insurance Group | 7.8% | 79 | +31.4% | +20.1% |
| W.R. Berkley | 2.8% | 76 | +5.2% | -6.1% |
| Nvidia | 0.6% | 76 | +39.2% | +27.9% |
| Alphabet | 0.1% | 83 | -3.3% | -14.5% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.