It is normal that in a price increase we have price corrections. This happens even in traditional markets.
But don't worry, it's still too early for the strong price corrections.
We will have all of 2021 and more with bull markets...
The market looks unstable right now and it could be there are some reasons why that happens. The correction doesn't matter so much as long as it can't break another below than 16k resistance. These days the whales are still waiting for something be that will be used as the reason to pump the bitcoin for sure.
More bullish market will come very soon. We is still in the early pump. I guess the this month will be the same as December 2017. Some management funds will be coming and there's a company who wanna put 500 millions into the bitcoin.