Efficient Markets and Wealth Emotions and Investing

Eliminating Market Risk

No matter how many stocks you own, you can't totally eliminate market risk. However, you can measure a stock's historical response to market movements and select those with a level of volatility you are comfortable with. Beta and standard deviation are two tools commonly used to measure stock risk.
Source: http://www.investorguide.com/igu-article-823-stock-basics-measuring-a-stocks-risk.html