问题如下：
Owen and Yang meet with Callie Steven, an upper
level executive with AutoPay, a small but fast growing privately held company.
She has been employed with AutoPay for more than 15 years and as a result, her
holdings in AutoPay are estimated to be more than 30% of her total portfolio.
She believes that over the next several years AutoPay will put together an
initial public offering, resulting in a huge windfall. She states that she has
a significant portion of her portfolio in short-term bonds and money market
funds to offset the risk of her AutoPay shares. Owen points out to Steven that
her current portfolio is subject to mental accounting, is not constructed in
layers, and does not take into consideration covariance between assets.
Is Owen’s comment regarding
Steven’s current portfolio correct?
选项：
A.No, he is incorrect with
regard to portfolio construction
Yes
C.No, he incorrect with regard
to covariance between assets
解释：
A is correct.
Owen’s comment regarding Steven’s current portfolio construction is not correct. Her current portfolio is subject to mental accounting, has been constructed in layers and does not take into consideration covariance between assets.
老师你好，请问分层抽样的方法，是不是只关注于每一层在特定概率下实现目标，有时候层内会用最优化，有时候不会用。
