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 | 57.1% | 74 | +17.6% | +4.9% |
| Markel Group | 52.2% | 88 | +10.3% | -2.5% |
| Berkshire Hathaway | 28.3% | 74 | +15.3% | +2.5% |
| Graham Holdings | 20.2% | 74 | +7.4% | -5.4% |
| Cincinnati Financial | 19.2% | 78 | +10.3% | -2.5% |
| Hingham Institution for Savings | 15.6% | 7 | +0.2% | +1.2% |
| White Mountains Insurance Group | 7.6% | 77 | +30.7% | +18% |
| W.R. Berkley | 2.8% | 74 | +4.9% | -7.9% |
| Nvidia | 0.6% | 74 | +56.7% | +44% |
| Alphabet | 0.1% | 81 | +0.6% | -12.1% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.