The retirement market in the US is worth $16,600bn (£8,000bn, €11,000bn), so it is no surprise that financial services companies of all shapes and sizes are scrambling for a piece of it.

However, according to a study to be released this month, retail banks face intense competition to capture affluent consumers' retirement assets. The study, conducted by the Bank Administration Institute, the industry body, and Mercatus, a Boston-based strategy consulting firm, found that only 14 per cent of consumers cited their bank as their primary provider of retirement savings, compared with 53 per cent for investment and brokerage firms.