Unlock the Editor’s Digest for freeRoula Khalaf, Editor of the FT, selects her favourite stories in this weekly newsletter.SoftBank has bought UK-based chipmaker Graphcore, as the Japanese tech group founded by Masayoshi Son accelerates its multibillion-dollar push into artificial intelligence. Graphcore, an AI-focused start-up that was founded by UK semiconductor industry veterans in 2016, will sit alongside chip designer Arm in SoftBank’s portfolio, as Son readies his “next big bet” in the tec...