I heard the proprietary firms trade against you in the other room. They make you buy only stocks they tell you to buy. You aren't allowed to pick your own stocks. Then they trade against you, so you lose. And they win twice from you, because you have to pay commission for your trades and desk fee's and software fee's and other misc. fees such as charting, news, etc..., to your proprietary firm you are working for.
Wow, that sounds like a great business model...more reasons to trade independently with Bright Trading, LOL. The so-called "job type" prop firms, from my discussions with traders, do tend to frown on pure discretionary trading, but it makes little sense to trade against their own traders since they still have to pay commissions to the Clearing firm, and don't charge their employees anyway (there a couple in the "gray area" between employee and discretionary, of course). If you think about it, why would domeone pay you to risk their money with all your own ideas? And, why would anyone who is good enough to make a lot of money with all their own trading skills want to give a Firm all the money? Doesn't make sense. But, as in most things, there are exceptions...and, yes, there are firms like GS who pay people to trade with some discretion. Don