Esops has become a standard plan for employee ownership plan in western countries . although esops in united states is recognized as a benefit that employers may provide to their employees under erisa of 1974 , the tax reduction act of 1975 and later legislation , it does not make promise to offer some kind of fixed income or bonus to employees . employee income will be related to the return in their investment to the company , which will be very incentive to the employee 现在， esops已成为西方员工持股制度的典型，虽然它也是美国众多福利计划的一种，但它不向员工保证提供某种固定收益或福利待遇，而是将员工的收益与其对企业的股权投资相联系，从而将员工个人的利益同企业的效益、管理和员工自身的努力等因素结合起来，因此带有明显的激励成分。
In 2004 , abs and mbs rated deals totaling $ 1 . 7 trillion dollars , which constituted over 7 . 5 % of total fixed income market . in the one hand , with the dramatic growth of international commercial trading , foreign currency asset have grown significantly in recent years . beside the simple derivative tools like : option , future , swap , the more effective financial instrument is need to protect against investment risk for foreign currency asset 广义上的资产支持证券包括的种类很多,现在美国大部份的缺乏流动性的金融资产都实现了证券化,这种新型的金融工具已经在国际金融市场上得到广泛的应用, 2004年在美国的资产支持证券和住房贷款抵押支持证券交易总额已经达到3 . 4万亿美元,占美国固定收益证券市场的份额为14 . 5 % 。
Consult the tolerance method of fix income security ' s market risk , we consequence and conclude the s - y approximate method of tolerance option ' s market risk base on the key theory of var parameter model , and it offer a theoretical foundation of option ' s market risk real time tolerance 参考固定收益证券的市场风险度量方法，在var (风险价值)参数模型的核心理论基础之上，推导并归纳总结出度量期权市场风险的-近似法，为期权市场风险的实时监控提供了理论依据。
