Commonly used practices:

1. Treat it as an investment, that is, simply go long or short.

2. Arbitrage. For example, you can do short-term arbitrage by taking advantage of time differences and price differences, or you can use the price difference between different currencies to make a profit by going around in a circle.

3. Mining, in fact, this should be an investment derivative, equivalent to futures. Of course, there are also websites that give away virtual currency for free, and you can earn hundreds of dollars a day.