always bitcoin decrease end of the year and start increase again by the beginning of the new year.
That was 2018. Have you forgotten the bull run from November 2017 to around January to February in 2018? Bitcoin moved from around $7K to the current all time high of $20K. So don't be too quick to make conclusions. Contrary to popular belief, We're already on track for the next bull run (- Bitcoins halving event and an expected alt season). So I feel it'll be different this time. The market sentiment is already getting positive with each passing day. It has moved from fear in January to Greed and now back to Neutral. You can see the Crypto fear and greed index
here