if you put your money in futures, it's not an investment, but it's trading, because even if you put the lowest possible leverage, there will still be the potential for a margin call. so it depends on you now, whether you are ready to risk €100 into the futures market, if you are ready then go ahead and put your money in futures trading. however, if you are not ready to lose that money, you can invest your money in the spot market, because whatever the price of bitcoin, as long as you don't sell it, you won't make a loss.
well to be honest if we try future and just decide to use lowest leverage ever then I guess we better off settle with spot trading instead.
its too much risk for a rather small profit to use future with lower leverage even though many people condone the use of just 1x leverage and thats it for the sake of safety but in my opinion we just better off using spot trading.
if its 3x like OP have mentioned it does still make sense, but know that with future trading once money is gone its gone, we're trying to stake our money on the margin, but it does have high return profile at the end of the day that many people are looking for.
its better if we can just adjust the capital at stake then increase leverage, even though arguably its the same profit using 3x leverage, but our money won't get drained in one go.
just to know the hang of using future trading with high leverage.