Application Rules：
1. A long upper shadow appears at the high point of an uptrend. If the trading volume increases, it indicates that the bulls are actively chasing higher prices, but the selling pressure at high levels is heavy, making it difficult for the stock price to climb higher. The market is likely to reverse or pull back.
2. A long upper shadow appears at the low point of a downtrend. If the trading volume increases, it indicates that the bulls are intervening to catch the bottom, but cannot effectively curb the selling pressure. Both bulls and bears have gradually turned into a state of balance.