What is long dollar

A long position is one that buys dollar contracts and is in a bullish position.

In other words, Chinese investors are bullish on the dollar and expect the dollar to rise, so they buy a certain amount of dollars at the current price, wait for a period of time after the dollar rises, hedge their contract positions at a higher price, so as to make profits.

A long position is when investors are bullish and expect the exchange rate to rise, so they buy at a low price and sell when the exchange rate rises to a certain level in order to gain the difference.