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 | 59.5% | 64 | -1.4% | -4.6% |
| Loews Corporation | 54.7% | 50 | -4.3% | -7.5% |
| Berkshire Hathaway | 28.1% | 50 | +2% | -1.2% |
| Graham Holdings | 22% | 50 | -1.1% | -4.3% |
| Cincinnati Financial | 21.5% | 58 | +2.9% | -0.3% |
| Hingham Institution for Savings | 21.2% | 74 | 0% | -3.2% |
| White Mountains Insurance Group | 6.9% | 52 | -12.1% | -15.3% |
| W.R. Berkley | 4.1% | 50 | +5.3% | +2.1% |
| Alphabet | 2.2% | 57 | -7.2% | -10.4% |
| Nvidia | 1% | 50 | -11.1% | -14.3% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.