Amazon said Thursday it projects revenue between $116 billion to $121 billion in the second quarter, trailing the $125.5 billion average analyst estimate, according to Refinitiv.

Amazon's core retail business has stalled as a flurry of online shopping tapers off amid the economy reopening from the pandemic. The company's operating expenses are increasing faster than its sales. Amazon invested heavily to staff up its warehouses and combat supply chain challenges, and it now faces rising inflation, as well as increasing transportation and labor costs.

The second-quarter forecast suggests revenue growth could dip to a range of 3% to 7% from a year earlier, representing a further slowdown from the first quarter, when revenue at Amazon increased 7%.

Amazon also lost about $3.8 billion in the first quarter, compared with a profit of $8.1 billion a year ago. The company's investment in electric vehicle maker Rivian weighed on its profits.

"While sales were short of expectations by a mere $6 million, the bigger headline was the company's first quarterly loss since 2015, at a loss per share of $7.56, or nearly $16.00 shy of the Street's earnings per share expectations," said William Blair analysts, who have an outperform rating on Amazon shares, in a note to clients on Thursday. "Under the hood, the company reported an $8 billion pretax loss related to its investment in Rivian Automotive. Recall the company reported a $12 billion benefit in the prior quarter related to the investment. We estimate the company's earnings per share excluding the investment-related loss would be roughly $3.40, still 60% below consensus as the company continues to face headwinds related to shipping, labor, excess capacity, and tough prior-year comparisons."