I have a question... do you think it's a good idea to invest BTC in futures now? With 3x leverage so as not to run as much liquidation risk?
If bitcoin is at $60000 and you long it with 3x, the liquidation would be around $40000. If you can take the risk, you can go for it.
Or do you think it's better to put my €100 in a wallet and wait?
The exchange that you use for the future trading can be hacked
I do not think bitcoin can go below $40000 again but anything is possible
You may think to increase the leverage which might lead to money loss, that is future trading.