I introduce you, RSJ a.s, worlds largest trader in size and volume
Largest counterparty at LIFFE, Eurex and maybe in 2 years also at ICE Futures Europe
Most people here favor prop shops like Getco or algo traders like RenTech. But none of you ever heard of RSJ a.s
Their trading volume exceeds EU6500 billion monthly and about EU80000 billion annually. I'm sure you've never heard of this size.