NEW YORK CITY, New York: The world's biggest technology companies have shed hundreds of billions of dollars in market value this year, as investors grow wary that massive spending on artificial intelligence may not deliver returns strong enough to justify high valuations.

Microsoft shares have fallen about 17 percent year-to-date, cutting roughly US$613 billion from its market value and leaving the company worth around $2.98 trillion as of February 13. The decline reflects concerns over risks to its AI business and intensifying competition from Google's Gemini model and Anthropic's Claude Cowork AI agent.

Amazon has dropped about 13.85 percent so far this year, erasing approximately $343 billion in market value and bringing its valuation to roughly $2.13 trillion. Earlier this month, the company said it expects capital spending to jump more than 50 percent this year.

Nvidia, Apple and Alphabet have also seen their market capitalizations decline since the start of 2026. Nvidia's value has fallen by $89.67 billion to $4.44 trillion, Apple's by $256.44 billion to $3.76 trillion, and Alphabet's by $87.96 billion to $3.7 trillion.

The retreat marks a shift in investor sentiment after years of strong gains driven by enthusiasm for AI. Markets appear to be moving away from rewarding long-term AI ambitions and toward demanding clearer evidence of near-term earnings returns.

In contrast, some companies outside the U.S. tech giants have gained ground. Taiwan Semiconductor Manufacturing Co., Samsung Electronics, and Walmart have added $293.89 billion, $272.88 billion, and $179.17 billion in market value this year, respectively, bringing their valuations to $1.58 trillion, $817 billion, and $1.07 trillion.