EARLY last year, Cheng Wei, founder and chief executive of the Chinese ride-hailing juggernaut Didi Chuxing, tried to resist taking money from legendary investor Masayoshi Son.

Mr Cheng told the SoftBank Group chief he didn't need the cash because his company had already raised US$10 billion, according to people familiar with the matter. Fine, Mr Son said, then suggested he might direct his support to one of Didi's rivals. Mr Cheng relented and took the investment: US$5 billion in the largest fundraising round ever for a tech startup.

Mr Son pulled a similar manoeuvre in November, publicly warning Uber Technologies that if he didn't get the deal he wanted, his backing would go to archrival Lyft. Uber also took the money in a US$9 billion investment unveiled last week.