buy low, sell high.
Depends partly on your personality, and partly on how much time you are willing to invest.
If you think crypto will be the future, and just want to buy some and forget about it for a few years, then holding is best.
Also trading isn't great if you are more risk-averse.
Trading is only best if you can afford to invest a lot of time as well as money, and have the right personality for it.