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 | 56.8% | 41 | +8.1% | -4.2% |
| Loews Corporation | 51.8% | 27 | -3.8% | -16.2% |
| Berkshire Hathaway | 26.9% | 27 | +7.5% | -4.9% |
| Cincinnati Financial | 21.7% | 31 | +10.9% | -1.5% |
| Graham Holdings | 21% | 27 | +8.3% | -4% |
| Hingham Institution for Savings | 14% | 57 | +10.7% | -1.7% |
| White Mountains Insurance Group | 6.7% | 30 | +6.3% | -6% |
| W.R. Berkley | 3.2% | 27 | +4.1% | -8.2% |
| Nvidia | 0.7% | 27 | +92.8% | +80.4% |
| Alphabet | 0.1% | 34 | +14.5% | +2.2% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.