The trading commissions will eat up all of your profits and professionals know that, so it's bad behavior.

交易佣金会吃掉你所有的利润,内行人知道这点,这是不道德的行为

耶鲁公开课 - 金融市场课程节选

If they're paid by commission on each trade they just keep calling you up and coming up with new ideas for new trades.

如果他们的薪水来自交易中抽取的佣金,他们就会不断拜访你,告诉你一些关于新交易的新点子

耶鲁公开课 - 金融市场课程节选