From how I see it, I believe there was big seller in the 20s who was offloading a lot of stock. From memory it was at 21.5-22c then later in the mid-teens. I can't forget how it was done quite systematically (but no bots) when there was a lot of volume. I think this is what triggered the sentiment that followed, and the general market has just amplified it.
Anyway I could be wrong but this really stands out in my mind.
