Sell hot buy cold, you mean? when an asset is hot it's bullish, when it gets cold it's bearish. Buying or hodling on a bullish run is an action that demands steady attention from the investors, they'd have to watch out for the bullish trend's expected duration before deciding to hodl or sell. As for assets with no potential market growth, the buyer must sell in a booming market and move on, it'll do no favor to return back, as the asset may never come up or get hot again.
We think of hot and cold positions in the market as bullish and bearish. When an asset reaches a peak of popularity, many people sell it, while there are some people who plan to buy and hold it, thinking about the future. In a bullish market, many investors make a profit by selling their saved coins, while many people buy in that market. Basically, it depends on the thoughts of each investor. The time of bullish and bearish must be analyzed, and later it must be planned to hold it, and investment must be made according to the growth of the market. If someone buys a popular currency from deep, then if he holds it for a long time and at some point that currency reaches the peak of popularity, then he should sell it. And if no one sells at that time and holds them with the aim of making more profit, then it can be a very wrong decision, because there are many assets that reach the peak of popularity and later fall completely and the price does not increase. So in every case, it is best to invest and sell them in a bullish market, otherwise there is a possibility of loss.