Recently, Fu Yongqiang, an investment consultant of Hexun, said that the performance nature of the large drop is that after the holder throws out the chips, the currency holder is unwilling to take over, thus forming a large black column with a large volume, which is usually manifested as a medium and large black line on the K-line chart. The essence of this pattern is that the bears are stronger than the bulls, and the market is panicked. Taking 7/0 as an example, the index experienced a large decline. According to common sense, the market should continue to fall after the volume drop, because in the process of the volume drop, another batch of new chips are trapped, and the panic usually continues, leading to further declines. At the level of actual trading, when encountering a sharp drop in stock volume, investors should not rush to buy the bottom. Under normal circumstances, the stock still needs to go through the process of shrinking to shrinking the small white line to stop falling, and only when the small white line of the shrinking amount stops falling, can it consider buying the bottom.