what does volatility refer to
Volatility is up-and-down movement of the market. It's usually measured by the standard deviation from the expectation. If you look at a day, the movement is typically up, but not by very much. Any movement up or down from its expectation is the volatility. Historically, the volatility of the stock market is roughly 20% a year and 5.8% a month, but volatility keeps on changing, so we go through periods of high volatility and low volatility. The biggest driver of volatility is a drop in the market.