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 |
|---|---|---|---|---|
| Markel Group | 58.9% | 41 | +0.3% | -1.7% |
| Loews Corporation | 54.6% | 27 | -2.2% | -4.2% |
| Berkshire Hathaway | 28.5% | 27 | +4% | +1.9% |
| Graham Holdings | 22.4% | 27 | -2.1% | -4.2% |
| Cincinnati Financial | 20.4% | 35 | +2.1% | +0.1% |
| Hingham Institution for Savings | 20% | 51 | +0.4% | -1.7% |
| White Mountains Insurance Group | 7.5% | 29 | -3.6% | -5.6% |
| W.R. Berkley | 4.1% | 27 | +6.8% | +4.8% |
| Alphabet | 2.1% | 34 | -13.5% | -15.5% |
| Nvidia | 1% | 27 | -18.4% | -20.5% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.