Alphabet shares hit a six-month low after Google disclosed that its AI-generated search summaries are eating into advertising revenue. Investors are increasingly worried that the company's core business is being undermined by its own AI push.

Anthropic, the company behind the Claude chatbot, told US regulators in its initial public offering filing that its own technology carries a 'catastrophic risk' to humanity. The disclosure makes Anthropic the first dedicated AI developer to pursue a US stock listing, with Alphabet and Amazon both named as existing investors.