Swing Index   

The Swing Index (Wilder) is a popular indicator that shows comparative price strength within a single instrument by comparing the current open, high, low and close prices with previous prices. This momentum indicator is used primarily as a component of the Accumulative Swing Index. The Swing Index alone doesn’t provide much in the way of signals. It should be used in conjunction with the Accumulative Swing Index
Usage:
It provides an indication of the real strength and direction of a price trend by providing a single indicator line, which can be analyzed for support and resistance lines.