The world’s largest investment banks may be under pressure from a new breed of high-frequency trading boutiques, as reported in Financial News last week, but a more established foe has been vacuuming up market share lost by the bulge-bracket firms in the past year.

Before the financial crisis, agency brokers and investment banks fought along established battle lines. The agency brokers were "independent", at least compared with the banks, because they did not have proprietary desks that could trade against customers.