New York - US stocks moved higher in opening trade on Tuesday but traders remained cautious ahead of the looming speech on the economy by Federal Reserve Chair Janet Yellen.
Shares of drugmaker Mylan however took a 3.2% hit after a powerful US senator questioned the skyrocketing price of its near-monopoly EpiPen, which severe allergy sufferers use to counter extreme allergic reactions.
About 10 minutes into trade, the Dow Jones Industrial Average was up 0.5% at 18 618.42.
The broader S&P 500 added 0.4% at 2 191.94, while the Nasdaq Composite, gained 0.4% at 5 267.59.