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 | 59.4% | 61 | -1.5% | -4% |
| Loews Corporation | 54.3% | 47 | -5.1% | -7.6% |
| Berkshire Hathaway | 28.2% | 47 | +1.9% | -0.6% |
| Graham Holdings | 22.4% | 47 | -1.4% | -3.9% |
| Cincinnati Financial | 21.4% | 55 | +2.2% | -0.3% |
| Hingham Institution for Savings | 21.1% | 71 | +0.3% | -2.2% |
| White Mountains Insurance Group | 6.8% | 49 | -13.5% | -16% |
| W.R. Berkley | 4.1% | 47 | +3.2% | +0.7% |
| Alphabet | 2.1% | 54 | -12.7% | -15.2% |
| Nvidia | 1% | 47 | -15.6% | -18.1% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.