Deviation rate (BIAS), by calculating the distance between the closing price and a moving average to reflect the reversal created by the degree of deviation between the price and the moving average during a certain period of time.
Above the zero axis is called positive deviation and belongs to the bullish zone, while below the zero axis is called negative deviation and belongs to the bearish zone.
Regardless of whether it is a positive deviation or a negative deviation, whenever the gap between the stock price and the moving average becomes larger, it means that the stock price has an overbought/oversold condition, and a high probability will result in a reversal.