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 | 59.3% | 14 | +3.8% | -0.4% |
| Loews Corporation | 57.2% | 91 | +11.9% | -6.7% |
| Berkshire Hathaway | 27.4% | 91 | +14% | -4.7% |
| Graham Holdings | 21.5% | 91 | +10.8% | -7.8% |
| Cincinnati Financial | 20.6% | 8 | +5.3% | +1.1% |
| Hingham Institution for Savings | 20.2% | 24 | +3.3% | -0.9% |
| White Mountains Insurance Group | 7.8% | 2 | +5% | +0.7% |
| W.R. Berkley | 3.1% | 91 | +5.2% | -13.4% |
| Alphabet | 2% | 7 | -16.7% | -20.9% |
| Nvidia | 0.6% | 91 | +85.5% | +66.9% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.