For the last forty years, variance and risk have become synonymous. Now they want to measure risk. So they say that volatility measures risk. And because it happened very fast, the beta of the stock had actually increased. The key to Ben Graham's approach to investing is not thinking of stocks as pieces of paper or as part of of the stock market.
Stocks are pieces of businesses.
If you want to be successful at focusing on business risk you have to be more like an insurance company. By knowing the business inside out and upside down, you also get the best handle on the risks involved. A stock may get clobbered in the short term, but it only means something if you sell it during that same time period. So, focus on the business, focus on the long run, and you won't have to focus as much on the returns. The Motley Fool.