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 | 55.9% | 55 | +11.8% | -2% |
| Markel Group | 53.6% | 69 | +9.9% | -3.9% |
| Berkshire Hathaway | 27.7% | 55 | +12.2% | -1.6% |
| Graham Holdings | 21.1% | 55 | +10.5% | -3.3% |
| Cincinnati Financial | 19% | 59 | +7.8% | -6% |
| Hingham Institution for Savings | 14.5% | 85 | +14.8% | +1% |
| White Mountains Insurance Group | 7.7% | 58 | +31.1% | +17.3% |
| W.R. Berkley | 3% | 55 | +4.7% | -9.1% |
| Nvidia | 0.7% | 55 | +89.1% | +75.3% |
| Alphabet | 0.1% | 62 | +12.1% | -1.7% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.