Amazon's shares topped a $3 trillion market capitalisation for the first time on Aug. 3. The gains extended after it reported second-quarter results last week that beat market expectations.

CNBC reported that Amazon shares ended up 5.37 percent, or $14.58, at $286.16, setting a record closing high. On a closing basis, it was the first time since May 6 that the stock set a new high.

The surge was driven by growth in its cloud business and expanding demand for artificial intelligence (AI). Amazon posted adjusted earnings per share of $1.97 in the second quarter, above the market estimate of $1.82. Revenue was $200.61 billion, topping the market forecast of $196.47 billion.

Amazon Web Services (AWS) revenue rose to $42.2 billion, well above the market estimate of $40.54 billion. Amazon said the second-quarter cloud growth was driven by rising AI demand.

Improving results also led to plans to step up investment. Chief Executive Andy Jassy (앤디 재시) said on the earnings conference call that memory prices are rising as AI infrastructure expands, and that it raised its capital spending outlook. Amazon put its full-year capital spending outlook at $220 billion. That was higher than the $200 billion it presented in February.

Jassy also said it still lacks enough capacity to meet demand. "Even if we invest at this scale, it will not be enough to meet all demand in 2026," he said. "We see this trend continuing in 2027," he added. "Demand already secured for 2028 is also surprising," he added.

Amazon's momentum is also seen across major cloud providers. Microsoft Azure cloud revenue rose 43 percent in fiscal fourth quarter, and Google Cloud said in an earnings release last week that it grew 82 percent.