Ok, so I know there are energy firms which actually actually have energy production units that trade proprietary capital in the energy markets (BP, Duke, formerly Enron, etc.). But I was wondering, are there any strictly proprietary trading firms that trade oil, gas, nat. gas, etc. I imagine some of these firms exist at the Nymex, and to lesser extent, maybe some trade on the screen? Does anyone know how common these types of firms are? I know energy contract trade in huge ticks ($1000 per in nat. gas, I believe).