I have seen OTC's trade premarket. No way these are posting from during the day. For instance last week when APPA received a CRL, Stock was down 50% premarket , trading was already 200k shares prior to open at the -50% price beginning at 8am. There would have been no trading during regular hours at -50%, so you must think there was some king of premarket trading going on that brought APPA down that far with that money shares traded, right?
I have done some research and it appears MM's can manually place orders and trade between themselves. Manipulation at its finest.