They're Market Makers. They make markets for this garbage and thousands of other stocks, all day every day. The day they stop doing that will be a joyous day, as that means this garbage, MDIN, will stop trading.
Shhh stop asking questions and finding out that MDIN is the victim of some serious manipulation. You're supposed to blindly accept it as a scam and not think that perhaps this dip is all part of a bigger picture of ebbs and flows. Like global warming.