U.S. stocks finished slightly higher Tuesday. The main indexes rose between 0.2% and 0.4%.
Apple(AAPL) shares extended gains in premarket trading Tuesday after rising 4.8% during the trading day. The stock rallied on news that investor Carl Icahn has taken a stake in the company, calling it "extremely undervalued."
Shares of BlackBerry(BBRY) were up 2% in premarket trading, as investors grow more confident that the struggling smartphone maker can find a way to keep the company afloat.