I believe the "market makers" here know this and are trying...

I believe the "market makers" here know this and are trying their best to flog SUM and SUMO until mgmt makes the big ANN. This is evident by the movement of the market depth through the day/week.

They have the money to build buy lines and trade between themselves, as soon as a stranger jumps in they will see this unknown volume and go to work by removing the buy lines and sell a small packet causing the underlying stock (SUM in this case) to drop (up to 10% on the day) this is a completely artificial environment and will only end when the mgmt team forces real volume through an announcement