随机漫步和有效市场假定 Random walk and the emh ■随机漫步-般票价格是随机的 Random Walk-stock prices are random Actually submartingale ■期望的价格在整个周期是正的 Expected price is positive over time 正向变化和随机变化 Positive trend and random about the trend12-4 随机漫步-股票价格是随机的 Random Walk - stock prices are random – Actually submartingale 期望的价格在整个周期是正的Expected price is positive over time 正向变化和随机变化Positive trend and random about the trend 随机漫步和有效市场假定 Random Walk and the EMH