The so-called short selling literally means forcing the empty side to buy. The word "forcing the air" comes from futures. It means that many parties are constantly pulling up, forcing the empty side to close the position. Because futures rise to a certain extent, the empty side will be forced to close the position. Borrowing from the stock market, it is used to describe that the rising stock price makes it impossible for short sellers to cover their positions at a price lower than their selling price, so they have to chase up at a high level and force the daily limit, which means to open the positive line twice: the stock price jumps to form the positive line, and the next day it opens with a gap and closes with a gap. This figure is a trend dominated by many parties, which generally indicates the collapse of bears, and the stock price may rise rapidly or even pull out the positive line. Investors should carefully observe the trend after the next day's high opening. If the stock price rises with the volume, you can intervene. At the same time, we should carefully observe the fundamentals and news of individual stocks, and beware of some main forces and institutions taking this form to defraud shipments.