Twentieth Century Volatility
回顾过去700年价格波动和100年股票波动，发现20世纪波动最剧烈，源于价格不稳定、金融危机、战争和政治动荡，建议投资者侧重风险管理而非预测未来。
The twentieth century was a turbulent time for equity investors. The author reviews price volatility over the past 700 years in general and equity volatility over the past 100 years in particular. The greatest sources of risk to equity investors in the twentieth century were price instability and resulting financial crises, wars, expropriations, and political upheavals. With respect to price volatility, the twentieth century was the most extreme by a wide margin with the most erratic price changes (deflation in the 1930s and inflation in the 1970s) occurring in the past 100 years. Given the unpredictability of past events, the author argues that an investment strategy biased on managing risk in the future could be a better approach to dealing with uncertainty than trying to guess what the future might hold.