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 | 54.4% | 55 | +8.3% | -3.6% |
| Loews Corporation | 52.7% | 41 | +2.4% | -9.5% |
| Berkshire Hathaway | 26.7% | 41 | +8.4% | -3.5% |
| Graham Holdings | 20.4% | 41 | +8.1% | -3.8% |
| Cincinnati Financial | 19.7% | 45 | +9.6% | -2.3% |
| Hingham Institution for Savings | 13.5% | 71 | +9.7% | -2.2% |
| White Mountains Insurance Group | 7.2% | 44 | +14.3% | +2.4% |
| W.R. Berkley | 3% | 41 | +3.1% | -8.9% |
| Nvidia | 0.8% | 41 | +122.9% | +111% |
| Alphabet | 0.1% | 48 | +7.3% | -4.6% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.