Filling the gap is a kind of short selling, which is the borrowing behavior of short sellers.

Affected by strong bullish or positive news, the opening price of the stock market is higher or lower than the closing price of the previous trading day, and there is a gap in the stock price trend, which is called a gap; In the trend after the stock price, the gap of the gap is covered, which is called filling the gap.

Short covering: Originally it was the stock market, but it was sold because of news or data. Short covering, refers to short positions at a high level, and buy positions when the price falls to a satisfactory level, resulting in a temporary rebound in prices, but unable to rebound to the original height. It is equivalent to a short profit.

Short covering refers to futures. Investors who were originally short in the foreign exchange market (short selling first) were forced to close their positions or go long (buy) by backhand when the trading direction and positions were reversed. Because investors are short, the direction of signing futures contracts is to sell, and they need to buy when they close their positions. In this way, the original bears became bulls, which contributed to the price increase. If the number of futures of a certain variety is relatively small and one party has sufficient funds, it is possible to continuously raise (or lower) the price, forcing the opponent to forcibly close the position, so that the price will continue to develop in a direction beneficial to him.

Seeing this, I believe you have understood the relationship between filling in the blanks and filling in the blanks.