Each index has its special parameter position, and each index has a special position with high accuracy, such as the golden cross of macd, the special position line of kdj and cci index. Then this paper will talk about the special position of roc index. What is the best parameter setting of roc index? The optimal parameter setting of roc index is generally three overbought lines, the first is overbought line (parameter value 5- 10), the second is overbought line (parameter value 12- 17), and the third is overbought line (parameter value 18-35). These three lines often imply the change of the whole market, so it should be noted that the first line is a pull-up signal, the second is a band signal, and the third is a strong signal. This is mainly because roc, a change rate indicator, measures the price momentum by calculating the ratio of the closing price change of the stock price in a certain period of time, combined with the comparison of price movements, so as to achieve the purpose of detecting the strength of supply and demand in stock price trading in advance. In this respect, it will have obvious practicability in judging the strength of the market in the short term. The above parameters and conditions are not immutable. We can set corresponding reference lines according to the plate size of different stocks in the general market, the activity of stock price fluctuation, the length of personal operation cycle and so on. In fact, the parameter setting of roc is judged according to the promotion degree of buying and whether selling follows. This index is essentially similar to the relationship between quantity and price, that is to say, there is no upper limit for the increase, and the increase in quantity and price should be followed, and the increase in shrinkage should be chased.