If you look at it in terms of € or $ it's not that bad. I bought bts end of August for 0.0029€, now it just spiked down to 0.0032€ and went up directely to 0.0035€.
Bitcoin is also very volatile, looking bts price in btc is not enought. IMHO, you also need to look at the price btc/fiat or bts/fiat.
The only problem is if you got margin margin call (I did
). But this is more a matter of trading risks that purely long term investment.