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 | 56.3% | 42 | +8% | -4.5% |
| Loews Corporation | 52.6% | 28 | -2% | -14.4% |
| Berkshire Hathaway | 27.2% | 28 | +8.2% | -4.3% |
| Cincinnati Financial | 21.2% | 32 | +11.2% | -1.2% |
| Graham Holdings | 18.6% | 28 | -3% | -15.5% |
| Hingham Institution for Savings | 13.8% | 58 | +10% | -2.5% |
| White Mountains Insurance Group | 6.8% | 31 | +6.6% | -5.9% |
| W.R. Berkley | 3.1% | 28 | +3.8% | -8.7% |
| Nvidia | 0.7% | 28 | +103% | +90.5% |
| Alphabet | 0.1% | 35 | +19.1% | +6.7% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.