Black, 47, a former professional gambler, launched Betfair, the online betting exchange, in 2000 with Ed Wray (qv). The London-based business floated on the stock market in October last year and is worth just over £1 billion. Black’s stake is worth £105m, to which we add £20m for past share sales and other assets. Not bad for a man who admits he didn’t have a job until he was 26.