The Financial Times chronicles a list of global banking luminaries flying their kite in fintech.They include Vikram Pandit, the former chief executive of Citigroup, and John Mack, the ex-boss of Morgan Stanley.Earlier this month, Blythe Masters, the former JPMorgan banker who pioneered the use of complex derivatives, was said to have turned down the job of running Barclays' investment bank to focus on Digital Asset Holdings, a New York-based start-up trying to cut banks' back-office costs by using technology associated with bitcoin.