They short the market. This strategy is very popular among crypoto speculators because of high volatility of crypto.
I believe that at the moment this strategy is not working since the uptrend has begun.
It is even easier for me to find a setup vs the market, since in this case the idea of an asset with this setup is clearly visible.
Based on my experience, I can say that it is not difficult to buy an asset, it is difficult to sell it at the right time.
And for me the hardest thing is to choose the right asset on the exchange that can potentially make a profit.