As you well know, nothing about the stock price going forward is guaranteed while taxes are guaranteed (tho I have no idea how close to guaranteed the change taking effect in 2021 is). Especially if the holder needs cash in January, they could cut .25/shr off a tax bill on $1.50/shr gain.
Alternatively, somebody might have bought into the runup above $2 and could be offsetting gains with very recent short term loss on the nwbo trade. They could cut their loss a little with tax balancing, and they could have bought the same number of shares for as low as near $1 after the big dump off of 2.50.
News 
Market Data 
Discover 
