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 | 55.9% | 57 | +11.6% | -3.6% |
| Markel Group | 54.2% | 71 | +10.8% | -4.4% |
| Berkshire Hathaway | 28% | 57 | +13.4% | -1.8% |
| Graham Holdings | 21% | 57 | +9.7% | -5.6% |
| Cincinnati Financial | 19.5% | 61 | +8.9% | -6.3% |
| Hingham Institution for Savings | 14.4% | 87 | +14.6% | -0.6% |
| White Mountains Insurance Group | 7.6% | 60 | +30.8% | +15.5% |
| W.R. Berkley | 2.9% | 57 | +3.9% | -11.3% |
| Nvidia | 0.7% | 57 | +89.4% | +74.2% |
| Alphabet | 0.1% | 64 | +10.8% | -4.4% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.