Question

If the expected returns of two stocks are the same but the standard deviations of the returns differ, which security is to be preferred

Answer 1

What you’re talking about is Beta. Beta is the ratio of how much a stock changes relative to the market as a whole (NYSE, NASDAQ)

A Beta of 2.0 means it changes (up/down) twice as much as the general market (Dow, S & P, NAS), such as the twitchy, hyper reactive tech stocks ( FAANG’s and also boom-or-bust Big Oil). In other words, high Standard Deviations.

A Beta of 0.5 means it changes (up/down) half as much as the general market. Sleepy blue chips such as GE, AT&T or power utilities fall in that category. Low Standard Deviations

Most stocks by definition pretty much track the market (Beta 1.0) so there are a lot of those. Middling Standard Deviations

So…it is dictated by your risk tolerance.