Bloomberg warns AI slowdown threatens $33T in stock gains

The S&P 500 has added roughly $33 trillion in market value since ChatGPT launched in late 2022. Now Bloomberg is flagging a scenario investors have mostly been trying not to think about: what happens if the fuel stops flowing. The trigger this time came from Anthropic CEO Dario Amodei, who on September 14 publicly called for a slowdown in AI development, citing safety risks. Elon Musk and Sam Altman have echoed similar sentiments at various points. Markets responded immediately. Nvidia fell 3.4% that day. SoftBank dropped 10.7%. The numbers behind the AI dependency According to Bloomberg Economics, AI-related investments contributed to roughly half of US GDP growth over the past year, with the economy expanding at around 2%. US VC funding topped $400 billion in the first half of 2026 alone, with AI startups capturing the lion’s share. Investor flows into IT-focused ETFs have surged to $52 billion since late March 2026. The rest of the market? A comparatively modest $4 billion. That’s a 13-to-1 ratio in favor of tech. Why safety concerns are spooking Wall Street When the CEO of one of the three leading frontier AI labs tells the world to slow down, it carries weight that a rando...