问题如下：
An investor invested $500 million in a hedge fund which has a "2 and 20" fee structure. Management fee is based on assets under management at year end, and incentive fee is based on 8% hurdle rate. At the year end, the hedge fund has appreciates 20%, what's the net return if incentive fee is calculated net of management fee?
选项：
A.12.49%.
B.15.68%.
C.18.32%.
解释：
B is correct.
要计算净收益，就要计算出总的各项费用：
年底的AUM=$500 million × (1+20%) = $600 million
因此，管理费= $600 million × 2% = $12 million，本题绩效奖是按照扣除完管理费的净值计算
扣除完管理费的净值=$600 million-$12 million=$588 million
考虑到8%的Hurdle rate要求，绩效奖计算基数=($588 − $500 *（1+8%））million=48million
绩效奖=48million*20%=$9.6 million
总的费用=($12 + $9.6) million = $21.6 million
净收益=($600 − $500 − $21.6) / $500 = 15.68%
如果没有特殊说明 的话，是默认用hard hurdle吗？
