A sudden wave of selling in major tech shares triggers doubt over the sustainability of the AI boom.

Traders work after a Federal Open Market Committee (FOMC) meeting on the floor of the New York Stock Exchange (NYSE) in New York, US, on Wednesday 17 June Financial markets received a sharp wake-up call on Tuesday following a sudden wave of selling in major technology shares, triggering widespread doubt over the sustainability of the AI boom. The tech-focused Nasdaq index fell about 2% alongside international chipmakers, reigniting fears that dizzying market valuations have finally run out of momentum after a relentless three-month climb. At the same time, the newly public SpaceX has faced an incredibly choppy session. The aerospace giant's share price plunged below the $150 (£114) mark– its initial floatation price–before staging a modest recovery to $157 despite the broader market anxiety. For months, international stock exchanges have climbed on pure optimism. While this enthusiasm repeatedly pushed indices to unprecedented highs, the sustained 90-day rally left stock prices looking incredibly inflated. On Tuesday, that upward drive vanished as market watchers questioned whether actual corporate adoption of AI can truly justify such expensive price tags. The downturn hit semiconductor players such as Nvidia and Intel the hardest, causing a primary index of global chip firms to slide. This turnaround follows a period where the wider tech sector had more than doubled stock prices from cyclical lows in 2022. It suggests that investors may have moved far too quickly to fund the hardware behind the AI shift.