Tri-Pack,
Taking a swing at someone will get you a fine for disorderly conduct. I wouldn't consider these fines a bad thing.
If you work on a trading floor long enough, sooner or later you're going to take a swing at someone or someone's going to take a swing at you. Or at least the thought of it will be given some very serious consideration.
Size does matter on the floor. You can get a trading floor job just for being over six feet tall. It's a physical job, and with all the pushing and shoving with money thrown into the mix, it's inevitable that a fight will break out once in a while.