Having watched the January 15th option chain before last week's monthly opex, you could see a significant number of deep ITM puts both being traded and showing

Having watched the January 15th option chain before last week's monthly opex, you could see a significant number of deep ITM puts both being traded and showing as open interest for lots of different strike prices. It's likely this created a short squeeze on Wednesday which caused these put sellers to take a loss, buy the underlying stock, or roll their contracts to a later date. Most of this price action occured on Wednesday, where there weren't volatile swings in either direction on Thursday or Friday.