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 | 55.7% | 48 | +9.1% | -3.8% |
| Loews Corporation | 52.9% | 34 | -1.1% | -13.9% |
| Berkshire Hathaway | 27.1% | 34 | +9% | -3.9% |
| Graham Holdings | 21.5% | 34 | +9% | -3.8% |
| Cincinnati Financial | 20.7% | 38 | +10.4% | -2.4% |
| Hingham Institution for Savings | 14.4% | 64 | +11.3% | -1.5% |
| White Mountains Insurance Group | 7% | 37 | +10.7% | -2.2% |
| W.R. Berkley | 3.1% | 34 | +2.4% | -10.4% |
| Nvidia | 0.8% | 34 | +113.7% | +100.9% |
| Alphabet | 0.1% | 41 | +15.6% | +2.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.