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 |
|---|---|---|---|---|
| Loews Corporation | 55.7% | 62 | +8.9% | -6.3% |
| Markel Group | 55.4% | 76 | +11.7% | -3.5% |
| Berkshire Hathaway | 28.9% | 62 | +15.7% | +0.5% |
| Graham Holdings | 20.8% | 62 | +10.7% | -4.5% |
| Cincinnati Financial | 20.2% | 66 | +8.7% | -6.4% |
| Hingham Institution for Savings | 14.7% | 92 | +16.2% | +1% |
| White Mountains Insurance Group | 8% | 65 | +35.4% | +20.3% |
| W.R. Berkley | 3% | 62 | +3.8% | -11.4% |
| Nvidia | 0.6% | 62 | +75.6% | +60.4% |
| Alphabet | 0.1% | 69 | +6% | -9.2% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.