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 | 55.4% | 56 | +10.8% | -4% |
| Markel Group | 54% | 70 | +10.4% | -4.3% |
| Berkshire Hathaway | 27.8% | 56 | +12.9% | -1.9% |
| Graham Holdings | 21% | 56 | +9.9% | -4.8% |
| Cincinnati Financial | 19.9% | 60 | +8.6% | -6.1% |
| Hingham Institution for Savings | 14.4% | 86 | +14.8% | +0% |
| White Mountains Insurance Group | 7.6% | 59 | +31% | +16.3% |
| W.R. Berkley | 3% | 56 | +4.4% | -10.3% |
| Nvidia | 0.7% | 56 | +93.3% | +78.5% |
| Alphabet | 0.1% | 63 | +13% | -1.7% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.