HoldcoTracker marks the 13-F equity portfolios of holding companies and operating businesses to last close — updated daily after market. The headline metric is each filer's equity book as a percentage of parent market cap, a number that doesn't exist anywhere else.
| Company | % of Mkt Cap | Days Since Filing | Since Filing | vs S&P |
|---|---|---|---|---|
| Markel Group | 56.8% | 14 | +10% | -4.1% |
| Loews Corporation | 52% | 87 | -8.3% | -17.9% |
| Berkshire Hathaway | 27.2% | 87 | +3.7% | -5.8% |
| Cincinnati Financial | 21.8% | 4 | +12.1% | -2% |
| Hingham Institution for Savings | 15.6% | 30 | +13.3% | -0.7% |
| W.R. Berkley | 6.1% | 91 | +16.1% | +6.5% |
| White Mountains Insurance Group | 6% | 3 | -0.1% | -14.1% |
| Nvidia | 0.6% | 87 | +150.3% | +140.7% |
| Alphabet | 0.1% | 7 | +22.5% | +8.4% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.