While other factors must be considered, the most basic use of the RSI values is to determine the best times to buy and sell high-quality stocks (note that low-quality stocks may have a low RSI because they are heading towards bankruptcy, not because they are undervalued). RSI is an indicator of price motion -- a low RSI roughly means the stock has been declining in price while a high RSI roughly means the stock has been increasing in price.

When the daily, weekly, and monthly RSI values for a ticker go below 30, that represents an Accumulation Zone, where it may make sense to start buying that equity. When the daily rises above 30, that is considered a Buy Alert, as it is a sign that the equity in question was at a cyclical low and is starting to rise again. For the opposite reasons, when the daily, weekly, and monthly RSI values are above 70 it is considered to be in a Distribution Zone, and a Sell Alert is when the daily RSI drops back below 70.

A final note of advice from Bill Cara's webpage: "I use the following technical indicators every day, but in combination with fundamental and quantitative studies plus a healthy dose of intuition and common sense. I never rely on technical studies alone -- and neither should you." The point being that these RSI calculations can help inform your investing, but it would not be wise to blindly follow what they say.