Of course Gox does their own trading, thats how they lost everyones money, by spending it on bitcoins which they turn around and dump back into the market at higher prices. Somewhere down the line they got too greedy and were unable to keep making money. Now they're trying to figure out if its better to quite while they are ahead an have people looking for them the rest of their lives, or to repay traders (investors) with their capital and start the ponzi over again.