An asset's standard deviation tells you how much its returns vary from its average. You can quickly calculate or look up the standard deviation of different assets. A high standard deviation can ...

Standard deviation measures how spread out numbers are from the mean. Variance calculates the average degree to which each number is different from the mean. Both metrics help assess volatility in ...

In response to my article, Is the Stock Market Too Concentrated?, which relied upon standard-deviation calculations to assess investment risk, a reader wrote: “My problem [with your argument] is ...