Yes I saw the same thing. Not normal for sure. It has happened 2 other times. Why? I don't know but my guess is at least two things allow for such large swings. There are individuals and small groups like Alpha, who care nothing about GNBT or NI-O or dividends. These folks only care about the momentum taking the price up and locked in profits. When they have hundreds of thousands of shares to sell and they have been buying(plus dividends maybe) for weeks or longer, they don't care what damage they do to liquidate. I haven't seen any filings yet to make me think a close insider is selling. I have no idea about any of the purchased companies, if they have to file anything. I would imagine there are restrictions in place on when they can sell. It might be in the public documents or not. I haven't read everything. One would think they would be holding at least through the GNBT up listing and AE spin off. I would also expect them to hire a professional trading firm to sell in a systematic way that doesn't do such perceived damage. They want a stable higher market to sell into. Of course, more likely they are in this for much bigger returns in a year or two.
Secondly,there are few buy orders with substantial size placed down below the current bid. It is quite easy for the price to go down. It takes a few minutes for the pps to arrive at a perceived value range before buy orders come in. For me, I had an order 2.50 in but it never got that far.
Maybe tc had a 50k share PURCHASE order in at 2.75 or better and the MM had to get it down there to get him filled!