然而，这些方法都是根据样本的变异数或报酬的共变异数估算的估计值。

However, these methods are estimated according to sample variance and covariance estimators of returns.

youdao

然而，这些方法都是根据样本的变异数或报酬的共变异数估算的估计值。

However, these methods are estimated according to sample variance and covariance estimators of returns.

youdao