I don't quite understand what you mean. The long-short ratio is a deceptive concept. Buy as much as you want, sell as much as you want, and have as many bulls as you want.

1 If you mean the ratio of long and short positions in SSE 50 stock index futures, there is theoretically no way to predict the stock market trend.

2. If you mean the long-short ratio index of stocks, there are many, and the most classic is the BBI index. Some long-short ratio indicators are compiled from the perspective of price, some from the perspective of quantity and energy, and some from the perspective of chip thinking. Generally speaking, it is for reference only and of little use.