Comparative Relative Strength (CRS)
Comparative Relative Strength parallels the price movement of a stock with an index, a sector, or another stock to show how they are conducting to one another relatively. CRS is obtained by dividing one security's price by a base (or second) price of the security. This division's result is the proportion or relationship between the two securities.
The security is performing better than the second security while the indicators are moving up. The stock and security are coming up and down with the same percentage the sideways movement appears. On the contrary, when the indicators are moving down, the security is not outperforming the base security.
You are advised to buy the best performer and sell the weaker one; this means the usage of the indicators to parallel a security's performance with a market index or to modify spreads.