For example, the definition of overbought area and oversold area in foreign exchange trading should be decided by investors according to the specific situation of the market. In the general market, RSI value above 80 can be called overbought area, and below 20 can be called overbought area. But sometimes in special ups and downs, the division of RSI overbought area depends on the specific situation. For example, in a bull market or bull stocks, the overbought area can be set above 90, and in a bear market or bear stocks, the overbought area can be set below 10 (this is relative to the RSI with small parameter setting. If the parameter setting is large, it is difficult for the RSI to reach above 90 and below 10).