大概这样:
P(t) = day t price
For continuous records:
Rolling Max(t) = Max { P(s): 0 <= s <= t}
For discreted time (say, daily data):
Rolling Max(0) = P(0)
Rolling Max(t) = Max[Rolling Max(t-1), P(t)]
Drowdown(t) = [P(t) - Rolling Max(t)] / Rolling Max(t)
我从 Yahoo Finance 下载了 S&P 500 Index daily close(没算分红再投资),用上面公式计算 Drawdown,图如下。我不负责上述公式的正确性,不负责数据正确性,也不负责我的计算是否符合上述公式。仅供大家参考