The decline of index funds means that the price of funds is falling. At this time, the cost of buying a fund is low. The lower the cost, the smaller the risk, and the greater the probability of obtaining income in the future. The fund is not suitable for buying when it rises. The higher the cost, the greater the risk and the greater the probability of losing money in the future.

Short selling, also known as short selling, is an investment term and a way of operating financial assets. Short selling is to borrow the underlying assets first, then sell them to get cash, and after a period of time, pay cash to buy the underlying assets and return them. The common functions of shorting are speculation, financing and hedging.