NO.PZ2015121810000012
问题如下:
What is the maximum Sharpe ratio that a manager can achieve by combining the S&P 500 benchmark portfolio and the Indigo Fund?
选项:
A.0.333
B.0.365
C.0.448
解释:
B is correct.
The highest squared Sharpe ratio of an actively managed portfolio is:
{$table2}The highest Sharpe ratio is
{$table3}考点:Sharpe ratio
解析: 求得是Indigo Fund与benchmark组合后的maximum Sharpe ratio。由于combined portfolio的Sharpe ratio不受激进程度的影响,因此无论当前的active risk是否处于optimal amount,Sharpe ratio的值不变。代入公式:
因此,SR=0.365。
投资组合和benchmark结合的portfolio里,不受benchmark权重的影响,算出来的sharp ratio都是一样的,这样的话何来“maximum Sharpe ratio”;只有optimal active risk才应该说“maximum”吧