ROC (Rate of Change) is a technical study available on most technical sites. The formula is (Pn-Po)/Po %, where n=no of back lookup period. The study takes current price and compares it with price n days before and expresses it as percentage of original price (Po). Thus if one sets n=100 days (20 trading days/month x 5 months) one gets approx % price change over 5 months. Just set ROC at n=100 and read off from graph. Stockchart provides this study.