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 | 58.8% | 49 | 0% | -2.1% |
| Loews Corporation | 55.7% | 35 | -0.5% | -2.6% |
| Berkshire Hathaway | 28.6% | 35 | +4.8% | +2.7% |
| Graham Holdings | 22.5% | 35 | -0.2% | -2.2% |
| Cincinnati Financial | 20.6% | 43 | +3.3% | +1.2% |
| Hingham Institution for Savings | 14.8% | 59 | -25.8% | -27.9% |
| White Mountains Insurance Group | 7.1% | 37 | -8.2% | -10.2% |
| W.R. Berkley | 4.1% | 35 | +5.4% | +3.3% |
| Alphabet | 2.1% | 42 | -9.5% | -11.5% |
| Nvidia | 1% | 35 | -17.5% | -19.6% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.