Venture investors are concentrating capital in artificial-intelligence start-ups at an unprecedented pace. PitchBook data show 41% of all U.S. venture dollars so far this year—roughly triple the 2024 share—went to just ten AI companies. Globally, Crunchbase estimates that one-third of the $91 billion deployed in the second quarter was channelled into the sector, the highest proportion in at least a decade. The rush is spilling into other asset classes. Twenty-three-year-old former OpenAI researcher Leopold Aschenbrenner raised $1.5 billion for the AI-focused hedge fund Situational Awareness, which posted a 47% net return in the first half of 2025. New thematic funds are emerging even as Goldman Sachs data show hedge funds broadly reducing exposure to large-cap technology shares last week. Corporate spending underscores the frenzy. Microsoft, Meta Platforms, Alphabet and Amazon are on track to commit about $350 billion in combined capital expenditure during their current fiscal years, much of it tied to data-centre construction and AI chips. The investment boom has propelled Nvidia’s market value above $4.4 trillion, briefly eclipsing Microsoft as the world’s most valuable company. Not every firm is benefitting. Bank of America warns that 26 publicly traded companies—ranging from web-development platform Wix to software giant Adobe—are particularly vulnerable to AI disruption; the basket has underperformed the S&P 500 by roughly 22 percentage points since mid-May. Similar fears contributed to a record weekly drop in Gartner after the research group cut revenue guidance. Economists say the surge in AI outlays is now the single biggest driver of U.S. growth, offsetting flagging consumer demand. While advocates argue the spending boom is grounded in tangible revenue gains at chipmakers and infrastructure providers, sceptics see echoes of past bubbles as valuations and deal velocity climb.