Unlock the Editor’s Digest for freeRoula Khalaf, Editor of the FT, selects her favourite stories in this weekly newsletter.Amazon has completed a $50bn investment in OpenAI, building a roughly 5 per cent stake in the ChatGPT maker ahead of a public listing expected next year.Amazon invested $15bn into the AI company led by Sam Altman in February as part of a broader commercial partnership. The ecommerce and cloud giant said it would invest a further $35bn if certain milestones, including a publi...