首先，暴跌的股价导致投资者账户中的股票下降到维持保证金水平以下，于是经纪商开始催缴保证金，迫使投资者甩卖更多资产以获得所需要的现金。
First, as plummeting stock prices caused the equity in investors’ accounts to fall below the maintenance margin, brokers began issuing margin calls, forcing investors to offload more assets to come up with the needed cash.