--it's stockholders equity plus preferred stock.

就是股东权益加上优先股
Then there's Tier II capital

然后又有了二级资本金
and then they have a formula

他们对此有个计算公式
--now, this is defined in Fabozzi.

如今这在法博齐的书中有定义
They have a formula that defines

有一个公式可以计算出
how much Tier I and Tier II capital a bank has to hold

一个银行到底需要持有多少一级和二级资本
and the amount depends on the risk class of their investments.

其数量取决于他们投资项目的风险等级
They define four credit risk categories

他们定义了四个风险等级
and they define a formula involving

然后根据每个风险等级下的资产额
the amount of assets in each of the categories.

定义了一个资产总额的计算公式
Then there's a formula that dictates

还有一个公式可以计算出
how much Tier I capital

他们必须持有