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 | 56.6% | 69 | +12.7% | -1.4% |
| Markel Group | 53.7% | 83 | +9.5% | -4.5% |
| Berkshire Hathaway | 28.6% | 69 | +14.9% | +0.9% |
| Graham Holdings | 20.8% | 69 | +7.5% | -6.5% |
| Cincinnati Financial | 19.6% | 73 | +9.6% | -4.4% |
| Hingham Institution for Savings | 14.9% | 2 | -1.2% | -1.4% |
| White Mountains Insurance Group | 7.6% | 72 | +29.9% | +15.9% |
| W.R. Berkley | 3% | 69 | +6.4% | -7.7% |
| Nvidia | 0.6% | 69 | +75.1% | +61.1% |
| Alphabet | 0.1% | 76 | +2.4% | -11.7% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.