In conjunction with stock valuation ratios like the price-to-earnings ratio and the price-to-earnings-growth ratio, a stock's beta can help investors build a diversified portfolio. Beta is a measure of a stock's volatility, and adding low-beta stocks to a portfolio can a be a great way to provide diversification.
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Benchmarking Beta
Using the S&P 500 as a benchmark for beta, investors can determine how a stock may perform in relation to a broad index. If a stock has a beta of 1, it is expected to move up and down in tandem with the benchmark. A stock with a beta of 1.10 is expected to rise or fall 10% more than the benchmark. Conversely, a stock with a beta of 0.80 would be expected to move up or down only 80% as much as the benchmark. In short, the higher the beta, the higher the stock's volatility.

And, by using beta to measure volatility, you can better choose securities that meet your criteria for risk. Investors who are very risk averse should put their money into investments with low betas such as blue chip stocks and Treasury bills. Those who are willing to take on more risk may want to invest in stocks with higher betas.

Here's a list of five high-beta stocks from the S&P 500 Index:

Company Beta Market Cap (Billions)
American International Group (NYSE:AIG) 3.42 53.07B
Genworth Financial(NYSE:GNW) 3.07 4.29B
Hartford Financial Services Group(NYSE:HIG) 2.98 9.38B
Wyndham Worldwide(NYSE:WYN) 2.95 6.52B
Principal Financial Group(NYSE:PFG) 2.74 8.71B
03/23/2012

Final Thoughts
By adding high beta stocks from the S&P 500, investors gain exposure to a cross-section of industries including basic materials, technology, chemicals and banking. The diversity is a great start, but investors should always remember to use beta as a guide to adding diversity and not as a guarantee of a stock's future price volatility. (To learn the basics of beta, read Beta: Know The Risk.)

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