Tech stocks tumble on concerns over AI spending

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.