Shares of large U.S. technology companies moved lower on Monday as questions about the scale and payback of artificial intelligence investments weighed on investor sentiment.
Alphabet led the slide, declining 6% and marking its biggest single-day percentage loss since May 2025. The fall put the company on course to surrender more than $256 billion in market capitalization.
At Google DeepMind, senior research scientist and Nobel laureate John Jumper announced he is leaving to join AI startup Anthropic. The departure was cited alongside the stock moves as part of the broader market reaction to developments in the AI sector.
Other major technology names also retreated. Amazon.com fell 4.8%, while Meta Platforms and Microsoft each slipped by about 3%. Together, those three companies were set to lose over $248 billion in market value.
Separately, SpaceX shares fell by more than 10% after sliding for three straight sessions following a post-IPO rally. The company disclosed on Monday that it is launching a notes offering.
Market participants noted that large cloud computing providers have committed billions of dollars to expand AI infrastructure. Those capital outlays have prompted investor concern about whether products developed using this capacity will generate returns sufficient to justify the expenditures.
The headline moves on Monday reflected both specific company developments and broader sector-level unease tied to AI deployment costs. Alphabet's steep intraday drop and the combined market-value declines at Amazon, Meta and Microsoft underscored how investor sensitivity to spending and talent shifts can translate into significant market capitalization changes across the technology complex.
Context and market reaction
- Alphabet: down 6%, largest one-day percentage decline since May 2025, on track to lose more than $256 billion in market capitalization.
- Amazon.com: down 4.8%.
- Meta Platforms and Microsoft: each down around 3%; combined with Amazon to be set to lose over $248 billion in market value.
- SpaceX: shares dropped more than 10% after three consecutive sessions of declines; company announced a notes offering on Monday.
- Google DeepMind: senior research scientist and Nobel laureate John Jumper announced he is leaving to join Anthropic.
Bottom line
Monday's trading highlighted investor scrutiny of AI-related spending across major technology companies and cloud providers, along with the market sensitivity to high-profile personnel moves and corporate financing activities.