There is something we can't escape from volatility, in fact, we live this thing since the day that ETH is created. But if we look at its fluctuating rate compared to the other altcoins, you can find that ETH didn't have that much volatility. If I have to invest Ethereum, I'll consider this as a long term investment rather than of short-term one because you can just make money if you can manage to hold it for a long time.