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 | 55.8% | 61 | +12.9% | -1.4% |
| Markel Group | 53.9% | 75 | +10.9% | -3.4% |
| Berkshire Hathaway | 28.1% | 61 | +14.3% | +0% |
| Graham Holdings | 20.7% | 61 | +10.5% | -3.8% |
| Cincinnati Financial | 19.1% | 65 | +8.5% | -5.8% |
| Hingham Institution for Savings | 14.5% | 91 | +14.8% | +0.5% |
| White Mountains Insurance Group | 7.9% | 64 | +34.4% | +20.1% |
| W.R. Berkley | 2.9% | 61 | +5.6% | -8.7% |
| Nvidia | 0.7% | 61 | +77.4% | +63.1% |
| Alphabet | 0.1% | 68 | +7.5% | -6.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.