SEATTLE — Amazon on Thursday reported net sales of $113.1 billion for the second quarter, an increase of 27% compared with the same period last year. That result fell short of analysts’ expectations, and the company’s stock fell in after-hours trading.

Like many retailers, Amazon is facing tough comparisons with 2020, when the pandemic drove huge sales gains for the online retailer. Amazon’s posted a year-over-year revenue gain of 41% in the second quarter of 2020.

“We do expect this pattern of difficult year-over-year revenue comps to continue for the next few quarters,” Amazon chief financial officer Brian Olsavsky said during a conference call. He noted that since May 15, excluding Prime Day, Amazon’s year-over-year growth rate has dropped into the mid-teens.

“Our Q3 revenue guidance range of 10% to 16% growth, reflects an expected continuation of this trend,” he said. “Given all this volatility is useful to consider the two-year compounded annual growth rate, which remains strong in the 25% to 30% range. Recall that this compares to our pre-pandemic growth rate of 21%.”

Net income increased to $7.8 billion in the second quarter, or $15.12 per diluted share, compared with $5.2 billion, or $10.30 per diluted share, in the second quarter of 2020.