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% | 13 | +3.4% | -0.1% |
| Loews Corporation | 56.4% | 90 | +10.8% | -7.1% |
| Berkshire Hathaway | 27.1% | 90 | +13.5% | -4.4% |
| Graham Holdings | 21.3% | 90 | +10.9% | -7% |
| Cincinnati Financial | 20.6% | 7 | +5.3% | +1.7% |
| Hingham Institution for Savings | 20% | 23 | +2.7% | -0.8% |
| White Mountains Insurance Group | 7.7% | 1 | +2.7% | -0.8% |
| W.R. Berkley | 3.1% | 90 | +5.2% | -12.7% |
| Alphabet | 2% | 6 | -14% | -17.5% |
| Nvidia | 0.6% | 90 | +82.7% | +64.8% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.