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 | 56.2% | 15 | +8.7% | -4% |
| Loews Corporation | 52.1% | 1 | -4.4% | -17% |
| Berkshire Hathaway | 27.2% | 1 | +7.7% | -4.9% |
| Cincinnati Financial | 21.5% | 5 | +11.4% | -1.3% |
| Hingham Institution for Savings | 15.7% | 31 | +13% | +0.3% |
| White Mountains Insurance Group | 5.9% | 4 | -0.6% | -13.3% |
| W.R. Berkley | 3.3% | 1 | +8.2% | -4.5% |
| Nvidia | 0.7% | 1 | +98.2% | +85.6% |
| Alphabet | 0.1% | 8 | +20.3% | +7.7% |
Data updates nightly after U.S. market close. 13-F positions reflect last quarterly filing; prices marked to most recent close.