Updated from 11:16 a.m. EDT Shares of Amazon.com ( AMZN) shed over 10% of their value on Friday following the company's disappointing earnings report. In an overall tough day for stocks, the company's shares closed down $5.80, or 12.7%, to $39.98. The stock's drop came one day after the e-commerce company missed Wall Street's earnings and revenue forecasts, and offered a disappointing outlook for the third and fourth quarters. While the company met its own guidance for the second quarter, it fell short of analysts' earnings expectations by a penny a share and their revenue forecast by some $50 million. In the just-completed quarter, the e-commerce giant earned $76.48 million, or 18 cents a share. That marked the fourth-straight quarterly profit for Amazon and compared favorably with the same period last year, when the company lost $43.31 million, or 11 cents a share. The company's revenue increased to $1.39 billion from $1.1 billion a year earlier. Excluding charges, the company would have earned $74.72 million, or 18 cents a share. While impressive, those results weren't enough to beat the Street's heady expectations . Analysts polled by Thomson First Call were expecting the company to earn 19 cents a share excluding charges -- 15 cents on a GAAP basis -- on $1.44 billion in sales. Amazon previously forecast that it would earn about 15 cents to 20 cents a share without charges on $1.34 billion to $1.44 billion in sales. On a conference call with reporters, Amazon CFO Tom Szkutak defended the company's results, noting that Amazon's results came in near the midpoint of its revenue and earnings guidance and ahead of its own forecast for "consolidated operating income," a proprietary metric used by the company that excludes certain charges. But Szkutak acknowledged that the company again benefited from the decline of the U.S. dollar vs. other major currencies. Had exchange rates remained constant with where they were in the second quarter last year, Amazon would have reported revenue that was $47 million lighter and net income that was $6 million, or 2 cents a share, lower.