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 | 57.5% | 68 | +14.3% | +0.1% |
| Markel Group | 53.3% | 82 | +9.8% | -4.4% |
| Berkshire Hathaway | 28.7% | 68 | +15.3% | +1.1% |
| Graham Holdings | 20.8% | 68 | +8.2% | -6% |
| Cincinnati Financial | 19.4% | 72 | +9.1% | -5.1% |
| Hingham Institution for Savings | 14.6% | 1 | -0.3% | -0.6% |
| White Mountains Insurance Group | 7.8% | 71 | +34.9% | +20.7% |
| W.R. Berkley | 3% | 68 | +5.7% | -8.6% |
| Nvidia | 0.7% | 68 | +78.5% | +64.3% |
| Alphabet | 0.1% | 75 | +3.1% | -11.1% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.