there is a huge different in stock exchange n gamble. stock exchange is usually depends on what is their decision and you predict whether it will be positive or negative. by looking up at news, you can roughly predict better in outcome. whereby gamble is mainly depend on luck.
Thats only true is gambling also have negative EV (playing vs unbeatable house edge).
Thats, however, is not the case. So there is no much diffence, "buying shares" is literally the same gambling at the core of thigs - you are risking x amount of money to make a profit, because you like the odds that it will happen.