When the market cap of a youthful market like cryptocurrencies goes from 18 billion to 116 billion in few months, one should expect a major correction. No one knows how to judge the value of Bitcoin yet to a tee and that's normal. There isn't enough to base it on, but the fundamentals are that this will reach the sky and this temporary breather is much needed.
It also provides an incredible opportunity to buy right now. Will probably hit 1500-1600 before rallying again. :)