維持保證金限制
maintenance requirement
在客戶的保證金帳戶中，必須維持的證券價值最低限度。也就是說，當保證證券的市場價值掉落限制之下時，帳戶所有人就會被通知補足證券。
In the customer's margin account, you must maintain the minimum value of the securities. That is, when the market value of the securities to ensure that fall below the limit, the account holder will be notified complement securities.