Short selling is an investment term for stocks and futures. For example, when you expect a stock to fall in the future, sell the stock you own when the current price is high (the actual transaction is to buy a put contract), and then buy it when the stock price falls to a certain extent and return it to the seller at the current price, so the difference is your profit.

Short RMB:

First, the RMB exchange rate was violently hyped. When the RMB exchange rate reached the highest level, it was sold for other currencies to obtain intermediate profits, which led to the RMB exchange frenzy in China and the overall economic downturn in China. Even the collapse of the government (that is, when these financiers make the peak value of 1 = 0. 1 RMB by means of speculation, they sell the RMB and exchange it for dollars to earn the difference).

The above is quoted from jyl3050 1.

Say what a hedge fund is:

Hedge fund, also known as hedge fund or arbitrage fund, refers to a financial fund that combines financial derivatives such as financial futures and financial options with financial institutions and obtains profits by means of high-risk speculation. It is a form of investment fund, which belongs to exempt market products. It means "risk hedge fund". Hedge funds are called funds, which are essentially different from mutual funds in terms of security, income and appreciation.

The above is quoted from the encyclopedia!

Therefore, it is not difficult to understand the significance of hedge funds shorting RMB.