It is a business that boomed to channel billions in fees to Wall Street firms as hedge-fund investments surged, then shrank last year amid fund losses and client withdrawals.

• 在对冲基金投资急剧增长的时期，这项业务给华尔街公司带来了数十亿美元的手续费，但随着去年基金普遍亏损，客户纷纷撤资，机构经纪业务也遭遇了下滑。