The ccass is one of the most important reforms to the risk management system introduced after the 1987 market crash . it is an automated book - entry system that handles the settlement of securities . in addition to brokers and custodians , ccass services are also available to retail investors 这套系统利用自动帐面记录系统处理证券交收工作,是一九八七年股灾以后风险管理系统方面最重大的改革之一。