Hedge funds have become the most significant single source of income for US equity brokers, accounting for almost a third of their total commissions, according to a study from Greenwich Associates.

Jay Bennett of consultancy Greenwich Associates, said: "Hedge funds now rank as the most important clients of many major equity brokerage houses, some of which might be generating as much as half of total revenues from hedge funds. Based on our research results and conversations with major brokers, we estimate that hedge funds could now account for as much as 30% of brokers' US equity commission flow."