Suppose you have 100 dollars. In the past, the US dollar was 1:8 against RMB. At that time, you changed all your dollars into RMB, so you had 800 RMB. At present, the USD/RMB is 1:6.5. At this time, if you change RMB into dollars, you have 123.08 dollars. You changed from 100 USD to 123.08 USD, which is a simple cash-out process. Of course, the specific process is more complicated than this. The meaning of hot money is very broad. My understanding is that in countries with slower economic development than China, their rich people do not make money at home as fast as China, so they are willing to invest their money in China to improve the speed of making money. This money can be understood as hot money. There should be other better understandings.