Casino cheats are thrown out, sometimes jailed. Market cheats are rewarded, given incentive and financed with tax payer dollars to run the scam all over again. Casino's have government oversight, rules and regulations. Current market conditions offer little of that, except for the retail trader. Lot's of rules and reg's for the little guy. Pretty much a free for all for the big boys.
So it pretty much depends on who is doing the trading. If you're one of the chosen few the fix is in and you'll make money no matter what. Any potential losses will be socialized among the masses and you'll be financed to gamble some more. At the end of the day the only people "trading" are retail. GS doesn't trade anything. They front OPM for a guaranteed return, one way or the other.