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 | 58.3% | 76 | -0.1% | -3.3% |
| Loews Corporation | 54.2% | 62 | -2.4% | -5.6% |
| Berkshire Hathaway | 27.6% | 62 | +4.6% | +1.5% |
| Hingham Institution for Savings | 22.2% | 86 | +4.1% | +0.9% |
| Graham Holdings | 21.9% | 62 | +1.6% | -1.5% |
| Cincinnati Financial | 21.4% | 70 | +5.7% | +2.5% |
| White Mountains Insurance Group | 7% | 64 | -7.4% | -10.6% |
| W.R. Berkley | 3.9% | 62 | +4.9% | +1.8% |
| Alphabet | 2.1% | 69 | -11.3% | -14.5% |
| Nvidia | 0.9% | 62 | -22.7% | -25.9% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.