问题如下:
If markets are semi-strong-form efficient, then passive portfolio management strategies are most likely to:
选项:
A. earn abnormal returns.
B. outperform active trading strategies.
C. underperform active trading strategies.
解释:
B is correct.
Costs associated with active trading strategies would be difficult to recover; thus, such active trading strategies would have difficulty outperforming passive strategies on a consistent after-cost basis.
请问这道题选项A为什么不对?