A indicator used by traders to gauge a security's long-term trend by comparing bars which contain its opening, closing, high and low prices throughout a specific period of time. When the ASI is positive, it suggests that the long-term trend will be higher, and when the ASI is negative, it suggests that the long-term trend will be lower.

The ASI is often cited as being developed by Welles Wilder.


|||While the ASI is most often used for futures trading, it can be used for analyzing the price trends of other assets as well. The ASI may be used in conjunction with price charts in order to confirm trendline breakouts, because the same trendline would be penetrated in both situations.