US markets tumble amid Wall Street concern over job losses and AI

S&P 500 down 1.1% and Nasdaq down 1.9% as hiring freezes and layoffs sharpen fears US economy is slowing

Fears that the US economy is slowing, with firms shedding jobs and imposing hiring freezes, sent Wall Street tumbling on Thursday.

The S&P 500 index of leading firms was down 1.1% as investors also highlighted concerns about the potential for a slump in the value of businesses that have benefited from huge investments in artificial intelligence. The tech-heavy Nasdaq Composite fell 1.9%.