Amazon significantly beat fourth-quarter 2021 earnings estimates but missed on revenue, reporting Thursday a profit gain of almost $12 billion from its investment in electric car company Rivian.

The tech giant’s stock closed Thursday at $2,776.91 per share, with it climbing more than 18% in after-hours trading. The regular U.S. stock markets will reopen Friday at 9:30 a.m. ET.

Wall Street analysts forecast earnings per share (EPS) of $3.58 on $137.56 billion in revenue for Amazon’s Q4, per Refinitiv data. The company reported $137.41 billion in revenue and net income of $14.32 billion — almost double year over year — translating into diluted earnings per share of $27.75, thanks to the Rivian investment.

Revenue for the quarter was up 9%, whereas the company’s revenue had grown 15% in Q3, 27% in Q2 and 44% in Q1. After some favorable adjustments that excluded the $1.3 billion impact from year-over-year changes in foreign exchange rates throughout the quarter, net sales increased to 10% for Q4.

Operating income decreased to $3.5 billion compared with $6.9 billion in Q4 2020.

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The tech giant revealed in its Q4 earnings results that it is hiking the price of its Prime service from $12.99 to $14.99. The company said: “With the continued expansion of Prime member benefits as well as the rise in wages and transportation costs, Amazon will increase the price of a Prime membership in the U.S., with the monthly fee going from $12.99 to $14.99, and the annual membership from $119 to $139.”

For the fourth quarter, Amazon subscription services revenue (which includes Prime memberships) was up 16%, to $8.12 billion. Ad sales growth, which Amazon broke out into its own segment for the first time in Q4, was 33% year over year at $9.7 billion. AWS, the cloud services division that Jassy previously oversaw, continued on a solid growth curve, with revenue rising 40%, to $17.8 billion.

“A big thank you to employees across Amazon who overcame another quarter of COVID-related challenges and delivered for customers this holiday season. Given the extraordinary growth we saw in 2020 when customers predominantly stayed home, and the fact that we’ve continued to grow on top of that in 2021, our Retail teammates have effectively operated in peak mode for almost two years. It’s been a tremendous effort, and I’m appreciative and proud of how hard our teams have worked to serve customers,” CEO Andy Jassy said in a prepared statement accompanying the financials. “As expected over the holidays, we saw higher costs driven by labor supply shortages and inflationary pressures, and these issues persisted into the first quarter due to Omicron. Despite these short-term challenges, we continue to feel optimistic and excited about the business as we emerge from the pandemic. When you combine how we’re staffing and scaling our fulfillment network to bring even faster delivery to more customers, the extraordinary growth of AWS with 40% year-over-year growth (and now a $71 billion revenue run rate), the addition of marquee new entertainment like The Lord of the Rings: The Rings of Power and Thursday Night Football, and a plethora of new capabilities that we’re building in areas like Alexa, Ring, Grocery, Pharmacy, Amazon Care, Kuiper, and Zoox, there’s a lot to look forward to in the months and years ahead.”

As of the end of Q4, Amazon had 1.608 million employees, up 24% from the year prior. The company said it paid $334 million cash in income taxes in the quarter, versus $420 million in Q4 2020.

Last May, Amazon announced a $8.45 billion bid for MGM, which is still pending regulatory approval. The ecommerce giant hopes to create new spinoffs based on MGM’s intellectual property.

For Q1, Amazon projects revenue to be “between $112.0 billion and $117.0 billion, or to grow between 3% and 8% compared with first quarter 2021.” That is accounting for an anticipated “unfavorable impact of approximately 150 basis points from foreign exchange rates.” Looking at operating income, Amazon expects “between $3.0 billion and $6.0 billion, compared with $8.9 billion in first quarter 2021,” guidance that “includes approximately $1.0 billion lower depreciation expense due to increases in the estimated useful lives of our servers and networking equipment” beginning Jan. 1.

Amazon will host a conference call with executives at 5:30 p.m. ET to discuss Q4 in greater detail.