SoftBank's ARM deal shows Masayoshi Son is in no rush to retire

Chief executive of Japanese technology giant had asked himself if he still had the energy for job; this takeover proves he does

Less than a month after the abrupt resignation of Masayoshi Son's anointed successor raised questions about SoftBank's appetite for overseas investments, the group has made its ambitions clear with a 24bn move on ARM Holdings, Britain's most successful technology company.

Monday's cash deal marks the start of the mobile technology company's quest to add semiconductors to its eclectic business portfolio and be a key part of the shift towards artificial intelligence, something that Son, SoftBank's chief executive, has described as "the biggest paradigm shift in human history".