All 30 Dow stock rise premarket, led by UnitedHealth

Shares of all 30 Dow Jones Industrial Average components were trading higher, as the three companies reporting earnings gave investors reason to cheer. The gainers were leb by the 2.3% jump in UnitedHealth Group Inc.'s stock after the insurer beat profit and revenue expectation. Johnson & Johnson's stock tacked on 0.8% and Goldman Sachs Group Inc. shares gained 0.9% after both companies beat profit and sales expectations. Merck & Co. shares were the second-biggest gainer, up 2.0%. Among other more active Dow stocks, Apple Inc.'s gained 0.6% and General Electric Co.'s tacked o 0.5%. Meanwhile, Dow futures rallied 217 points.