Apple's (NASDAQ:AAPL) latest earnings release has now hit the wire, and investors aren't happy. Shares fell more than $40 in after hours trading as iPhone unit sales came in shy of expectations. Apple sold 51 million iPhones during the holiday quarter, while investors were hoping for at least 55 million. On the bright side, iPad units came in fairly strong at 26 million.

On top of that, guidance for the current quarter calls for revenue in the range of $42 billion to $44 billion, also shy of market expectations. Total revenue came in at $57.6 billion, with earnings per share of $14.50. Both the top and bottom figures were able to beat estimates, but that wasn't enough to overcome the shortfall in iPhone unit sales. iPhone average selling prices put up a nice gain sequentially, which lends to the hypothesis that the iPhone 5c is pushing demand toward the iPhone 5s. Even if the product mix is shifting favorably, overall unit sales are still short of what investors were expecting.

In the following video, Evan Niu discusses Apple's latest earnings with Fool contributor Ashraf Eassa.