Learn the differences between Z-Score and Standard Deviation. Discover how they are calculated and used to evaluate market ...

When you have the average production of three machines, it is easy to calculate the average or mean production. You just add ...

Volatility is troublesome for many investors. Value changes in your stocks, your portfolio, or an index can keep you up at night -- or worse, push you to make emotional decisions you later regret.

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 ...

Investopedia contributors come from a range of backgrounds, and over 25 years there have been thousands of expert writers and editors who have contributed. Somer G. Anderson is CPA, doctor of ...