It all depends on how much you mitigate the risk.
If you don't look both ways before you cross the street, that would be gambling. If you don't stop at a red light, that would be gambling.
If you work hard at trading, study, adhere to the rules you set forth, that would be speculating (trading)
Much in life has an element of risk...The key as to whether something becomes "a gamble" or not has much to do with mitigating that risk.