BTC should no longer be considered a viable long term investment (it hasn't for quite a while now, but today proves it even more) The price fluctuates quite a lot and anyone who is trying to legitimately invest has a high risk of loosing money.
But, here's the thing. It's a new enough, and important enough thing that it is bound to go back up, do the smart thing, buy it up now, when it's at it's low, ride it up, second it stops riding, sell it out.
Just don't go too wild, what this entire post is saying is that it is for the most part BTC is extremely unpredictable. I'm sure it will go up but no telling how long it will take to rebound. Or by how much.
BTC hasn't been a viable investment for some time. It's volatility is the root cause of that. You're more likely to lose money than gain money if you invest in BTC.
... and for two, cryptocurrencies aren't an appreciating asset. You're right, BTC is just way too volatile. If you believed in the project in 2012 - 2013 you would have been fine going into it as a long-term investment but these days the price of BTC is astronomical and all over the place.
I'd rather invest in something like Ethereum or Ripple and HOPE it hits prices like BTC did someday.