Yes, the vast majority of traders are gamblers, maybe the majority of market participants are in fact gamblers. The traders that are gamblers trade with no plan and without understanding the odds are stacked against them. Whether it is buying far out of the money options with no method for profitability or randomly chasing stocks on a whim, gambling is when you risk money with the odds against you and have no edge. The losses of the gamblers is where the majority of the profits come from to the winning traders in the markets who have an edge.
Now the other side is the traders that consistently win by using an edge that gives them an advantage over the other traders. The winning traders are not trading against the casino they are trading against the gamblers. They have become the casino, like the casino they know the odds are in their favor and they will be profitable in the long run. Like the casino has table limits they have risk management to not over expose themselves to any one bet by the gamblers. The biggest problem that gamblers have is their emotions that cause them to always lose in the long term by placing bets based on feelings instead of the odds. The winning traders trade based on probabilities being in their favor and pick their trades carefully based on the best chances of success.
The casinos are built from the losses of the gamblers, the winning traders accounts are built on the gambling of the traders with no plan, no edge, and no risk management.