I will just state my experience from trading main markets which is the news is written after the market moves and they try to describe why its done that.    There is a tiny cutting edge of sellers who will have a direct feed on reuters brief breaking news releases and sure some might act in that way but most of us are not selling for this reason as we cannot justify sitting by a ticker machine watching even an expected decision.  
  Its always going to be a combination of factors, this current sell off was predictable as early as July when we peaked and lost the previous months trend up.   The trend where we gained was so aggressive we quickly went from 3k to 13k and it could not continue in any sensible way as markets never move in one direction perfectly simply unless they are broken, it would add up to free money.   We'll have an adjustment up again some time in future and this recently has been some adjustment down and its a good thing because BTC is more real when it does both, long term its positive Iam sure of it.     Thankfully BTC is not broken and its adjusted, eventually after some months we have a final wave of doubt and the worst prices are observed.   I would compare this to the tail end of a bull whip, the most rapid movement comes at the end but the wave first started a while back.  
  News doesn't really describe market moves, some stories grow and there is an iterative effect perhaps but there is no one story imo.