One of the most profitable hedge funds has closed its doors to new clients, calling time on the industryâ??s ability to square vast inflows of money with the promise of market-beating returns.

DE Shawâ??s move means that of the largest six hedge funds, only two, the UKâ??s Man Group and the US firm Och-Ziff, are still accepting cash into their flagship funds. Many traditional hedge fund strategies have become far less profitable due to quantitative easing, bank deleveraging and a tail-off in corporate dealmaking.

DE Shaw is mainly known for its style of using mathematical and statistical modelling to spot investment opportunities â?? a legacy left by founder David Shaw, a mathematician who resigned from the day-to-day running of the firm in 2002.