RE:RE:RE:RE:Let's put this into Perspective These are brokers, too. You don't know if they are trading on behalf of a customer or on their own. Personally I don't think they are - GCU is way too small.
I don't think this was a (professional) algo going berserk, volume not worth to mention:
To me it seems much like a market order placed into illiquid bids. More like a small retail investor who lost nerves and wanted to get out at the end of the trading day. Maybe induced by breaking 0,20.
I think more interesting is the changing of hands around 0,20. Locking in some losses for tax loss reclamation at end of year?