AI boom races ahead as costs and risks mount

The AI market is entering another speculative peak as SpaceX seeks a $1.77tn (£1.31tn) US stock market valuation, Anthropic files for an IPO, and OpenAI is expected to follow. The rally has helped lift the S&P 500 by nearly 80% over the past five years, with 41 AI-related stocks accounting for nearly half its market value, according to Bianco Research.

Infrastructure spending is accelerating from $765bn this year to $1.6tn in 2031, according to Goldman Sachs, as companies pour money into datacentres, chips and related systems. Adoption is also broadening: McKinsey says company use has risen from 33% in 2023 to nearly 80% now, while Sensor Tower data puts ChatGPT at 1bn monthly active users.

Even so, questions over returns are mounting. Token prices include $5 a million input tokens for GPT-5.5 and $30 a million output tokens, while Axios reported one unnamed company spent $500m in a month on Claude Code licences. Anthropic’s Claude is gaining traffic quickly, but AI developers still need to show that tools can improve productivity enough to justify costs.

The boom is also straining physical capacity and the wider economy. Bloomberg estimated 23GW of datacentre capacity under construction globally in 2025, while JLL expects 100GW to be added between 2026 and 2030, equivalent to 1,200 datacentres. Datacentres are already a major growth engine: a Harvard economist calculated that “investment in information processing equipment & software” accounted for 92% of US GDP growth in the first half of 2025.