“More likely I think, the Big Shorty covered the rest/last of its Short position at the last possible moment before anyone found out they covered 3MM shares already.”
That is a very likely event. It’s either that or news of a partner/buyout. I’m leaning to partner/buyout. Premarket trades will indicate the reason. If premarket is huge volume then it is a partner/buyout news. I would think the shorts would have use options last week as a prelude to covering.
I also believe a partner is most likely because that is the next critical step for EU approval.
News 
Market Data 
Discover 
