It's not really that simple. It is clear that the rate of cryptocurrencies can fluctuate a lot, but this does not mean that a small decrease is a signal to immediately sell. But on the other hand, if you wait, you might miss a good moment. In any case, in the end, the decision will have to be made by you. And to sell, you can go to the crypto exchange Nimlab:
https://nimlab.eu/ .