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 | 54.5% | 54 | +8.2% | -3.8% |
| Loews Corporation | 53.3% | 40 | +2.3% | -9.8% |
| Berkshire Hathaway | 26.8% | 40 | +8.2% | -3.8% |
| Graham Holdings | 20.8% | 40 | +7.7% | -4.3% |
| Cincinnati Financial | 20% | 44 | +9.7% | -2.3% |
| Hingham Institution for Savings | 13.7% | 70 | +9.4% | -2.7% |
| White Mountains Insurance Group | 7% | 43 | +12% | 0% |
| W.R. Berkley | 3.1% | 40 | +4.7% | -7.3% |
| Nvidia | 0.8% | 40 | +124.3% | +112.3% |
| Alphabet | 0.1% | 47 | +11.1% | -0.9% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.