Hi 
Since I have seen this transaction (which was part of a $-25-Mio-Issue on a DeFi project called xToken) I am thinking about it: 0x7cc7d935d895980cdd905b2a134597fb91004b5d551d6db0fb265e3d9840da22
It contains a bunch of expensive transactions through the wide field of DeFi space, but costed itself not a single Wei of Gas. How could that be?
I have seen on Ethercan, that it is called a “private transaction”, which was “bypassing the mempool”.
What are the requirements to submit such an transaction and even to get it into the chain accepted by other miners? It seems to me that the folks behind this transaction were their own miners, but how could they get it broadcasted into the network without the power of a bigger pool? Or was this a coordinated effort by multiple participants across several mining pools?
Thank you in advance for any thoughts that may help me here in order to understand.