Friedman, Billings, Ramsey (FBR), an investment bank, reckons trading commissions have plummeted by almost a third since 2000, and by even more if higher-margin option trades are excluded.

• 投资银行Friedman,Billings,Ramsey(FBR)估计交易佣金较2000年已骤降三分之一，如果有更高利润的期权交易未被计算在内的话，下跌幅度将会更大。