This is actually such a HIGH IQ yet scummy scam.
So from my knowledge, basically this is how he does it:

1. He has both of his accounts in one map, and on one he says "Buying ZHulong 50M" (example)

2. On his other account (tecnique), he says "Selling Zhulong 35m", right?

So basically, people will try tobuy the zhulong for 35m from his Tecnique account, and sell it for 50M on his Mark account.

DAMN he smart, but yeh hella scummy.