Amazon.com, Inc. (AMZN) shares traded lower after reporting a second-quarter sales miss.

Earnings came in at $5.22, which may not compare to the $5.58 estimate. Sales came in at $63.4 billion, beating estimates by $940 million.

The company sees third-quarter sales of $66 billion-$70 billion compared to the $673 billion estimate.

"Customers are responding to Prime's move to one-day delivery — we've received a lot of positive feedback and seen accelerating sales growth," said Jeff Bezos, Amazon founder and CEO. "Free one-day delivery is now available to Prime members on more than ten million items, and we're just getting started. A big thank you to the team for continuing to make life easier for customers."

Highlights

• Prime Day was the largest shopping event in company history
• Net sales increased 20% year-over-year
• Operating income increased to $3.1 billion

Amazon shares traded down 1.5% to $1,950 in Thursday's after-hours session. The stock closed at $1,973.82.