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 | 57.8% | 67 | +15% | +1.8% |
| Markel Group | 53.1% | 81 | +10.1% | -3.1% |
| Berkshire Hathaway | 28.6% | 67 | +15.2% | +2% |
| Graham Holdings | 20.8% | 67 | +9.1% | -4.1% |
| Cincinnati Financial | 19.3% | 71 | +8.7% | -4.5% |
| Hingham Institution for Savings | 14.4% | 97 | +14.8% | +1.6% |
| White Mountains Insurance Group | 7.8% | 70 | +35% | +21.8% |
| W.R. Berkley | 3% | 67 | +5.7% | -7.5% |
| Nvidia | 0.6% | 67 | +64.6% | +51.4% |
| Alphabet | 0.1% | 74 | +0.4% | -12.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.