Apple reporting earnings after the closing bell on Thursday. CFRA's Angelo Zino says he has his eyes on iPhone sales. Analysts are expecting revenue to surge, with an estimate of more than $50 billion for the quarter. That would be an increase of 8 percent year-over-year. FactSet research is estimating 46 million iPhone unit sales for the quarter. CFRA predicts iPhone sales to contribute to more than half of total revenue for Apple. CFRA maintains a "buy" opinion of Apple ahead of this earnings report.