NEW YORK, United States (AFP) — Shares of Microsoft spiked Thursday following blowout quarterly results, lifting the tech giant into the previously unprecedented $4 trillion club along with Nvidia, another artificial intelligence (AI) standout.

The landmark valuation is the latest sign of growing bullishness about an AI investment boom that market watchers believe is still in the early stages — even as companies like Microsoft plan $100 billion or more in annual capital spending to add new capacity.

Microsoft reported profit of $27.2 billion on revenue of $76.4 billion in its fiscal fourth quarter, capping another year of growth amid massive customer interest in the company’s cutting-edge AI capacity.

Shortly after midday, Microsoft shares were up 4.3 percent, giving it a market capitalization slightly under $4 trillion after earlier eclipsing the benchmark.

“Cloud and AI is the driving force of business transformation across every industry and sector,” said Microsoft CEO Satya Nadella. “We’re innovating across the tech stack to help customers adapt and grow in this new era.”

The results drew plaudits from Wall Street analysts on an earnings conference call at which Nadella boasted that the company had opened new data centers across six continents in the last year and touted major contracts for global companies like Nestle and Barclays.