It mostly looks to be from stock manipulation. Day traders mostly.
On low volume days it's easy to manipulate the stock. All they need to do is strategically place a few carefully timed trades in order to trick people and create the illusion that a stock price is moving so they can then get others to buy or sell. The end game is to move the price higher if the day trader wants to sell and lower the price if they want to buy. If you are tricked by this, then your position can quickly turn into a loss.