Opening Bell: Stocks Rise Despite Fed Rate Hike Fears; Apple Orders More iPhones

U.S. stocks opened higher on Tuesday, despite additional chatter from Federal Reserve officials that a rate hike may come sooner-than-expected. Plus, Best Buy (BBY) - Get Report shares fell 6 percent on news the company isn't raising its full-year guidance. The company's first quarter same store sales were flat, which was better than the 1-2 percent decline analysts had expected. Best Buy has been threatened from online retailers like Amazon (AMZN) - Get Report . Meanwhile, Apple (AAPL) - Get Report reportedly told its suppliers to build 72 million-78 million iPhone's this year, according to a Barron's report. iPhone sales have been softening in recent months. Finally, a new study from California State Polytechnic University, Pomona said Fitbit (FIT) - Get Report heart rate monitors are 'highly inaccurate.' Fitbit is facing a class action lawsuit over the monitors and the law firm representing the plaintiffs commissioned the survey. TheStreet's Scott Gamm reports from Wall Street.