If Bitcoin could grow from 4000$ on September 2017 to 19800$ on 17 December 2017, then it's not a big deal for Ethereum to grow back to 1000-1500$in few months.
It will not be a problem if someone invests billions of dollars into the crypto currency market. This requires increased interest from the public. Now we see the reverse process. Many people are disappointed in the crypto currency and spread the negative among friends and acquaintances. It will take time for the market to recover.