Description:   As the multi-space index is developed on the basis of the moving average, it can also be applied in accordance with the Gramwell's Law, as follows: 1. When the stock price is in the low position, once the closing price breaks through the long-short index, it is a buy signal. 2. When the stock price (or index) is in a high position, once the closing price (or closing index) falls below the long-short index, it is a sell signal.