How to use beta to evaluate a stock’s risk

1
svetikd/Getty Images
Bankrate Logo

Why you can trust Bankrate

While we adhere to strict , this post may contain references to products from our partners. Here's an explanation for .

When you invest money, be prepared to encounter bumps along the way. The stock market moves up and down all the time, but the individual stocks that comprise the market all move at different paces. Some might have higher highs and lower lows, and others might move in nearly identical fashion to the market as a whole. Will a stock feel like a roller-coaster ride? Or will it feel more like you’re driving on a highway at the same pace as the car next to you? Its beta can offer helpful cues.

What is beta, and how does it work?

Beta is a way of measuring a stock’s volatility compared with the overall market’s volatility. The market as a whole has a beta of 1. Stocks with a value greater than 1 are more volatile than the market (meaning they will generally go up more than the market goes up, and go down more than the market goes down). Stocks with a beta of less than 1 have a smoother ride as their moves are more muted than the market’s.

Using beta to evaluate a stock’s risk

Beta allows for a good comparison between an individual stock and a market-tracking index fund, but it doesn’t offer a complete portrait of a stock’s risk. Instead, it’s a look at its level of volatility, and it’s important to note that volatility can be good and bad. Investors aren’t complaining about upward price movements. The downward price movement, of course, will keep people up at night.

Think of comparing the beta of different stocks in the same way you might order food at a restaurant. If you are a more risk-averse investor who is focused on earning income, you might shy away from high-beta stocks the same way that someone with a simpler palate might prefer to order a plain dish with familiar ingredients and flavors. A more aggressive investor with a higher risk tolerance might be more inclined to chase the high-beta stocks the same way an adventurous eater will look for new, spicy dishes with exotic ingredients they have never tried.

Beta is a data point that is widely available. You’ll find this alongside other metrics of a stock’s price when doing your research — which you should always do.

Pros and cons of using beta

Pros

  • History can hold important lessons: Beta uses a sizable chunk of data. Reflecting at least 36 months of measurements, beta gives you an idea of how the stock has moved vs the market over the last 3 years.
  • Numbers don’t lie: Rather than combing through press releases about past product launches or trying to read between the lines of what a company’s CEO might have said at the investor day last year, and how the stock reacted to these various pieces of news, beta mathematically represents the stock’s moves for you.

Cons

  • You’re looking in the rearview mirror: Beta is a backward-looking, singular measure that doesn’t incorporate any other information. Sure, it’s good to reflect on what the past three years looked like, but as an investor, what you care about is what’s in store for the next three years. You want to think about business prospects and potential market disruptions on the horizon. This is why beta is only one part of your research.
  • Numbers aren’t everything: Beta doesn’t include qualitative factors that can play a significant role in a company’s outlook. Did that renowned CEO step down during those three years? Now that the succession plan is in place, perhaps the future will look quite a bit different.
  • The measurement doesn’t work with young companies: As plenty of hype swirls around IPOs, beta is one number that will never be part of the conversation. Because it’s calculated on historical price movements, you can’t use beta to evaluate companies that have plans to go public or young companies that have recently been listed on Wall Street.
Written by
Greg McBride, CFA
Chief financial analyst
Greg McBride, CFA, is Senior Vice President, Chief Financial Analyst, for Bankrate.com. He leads a team responsible for researching financial products, providing analysis, and advice on personal finance to a vast consumer audience.
Edited by
Senior editorial director
Reviewed by
Allyson Johnson
Head of investor relations, Gateway Partners