Let's switch things up a bit. 7 users instead of 6  - remember, after a while users won't have much incentive to bet in the market. 

A proof-of-concept that allows a silly picking-pennies-up-off-the-ground attack on some automated traders as they apparently currently exist. Getting 7 participants implies that I'm picking up pennies off the ground for every run of this market (+$M10 from the system bonus) and you're picking up pennies off the ground that an easily-taunted trading bot drops on the floor. You're effectively betting against the bots' programming getting more sophisticated before close (assuming someone bothers to try to attack the bots somehow).

May close early if YES. This is a rerun of the experiment to see if the exploit still is viable.