I think trading is also part of gambling. But in the midst of the general public trading is not gambling . I never heard my government forbids people to do trading, even a lot of advertising on tv who advise people to trade in their place. So it could be said trading is part of gambling but it could also be said not, depending from what angle we view it.
In deep meaning trading really similar to gambling in some aspects.
But one more time, it is only if you dig so deep about what trading it is and how to trading etc. General understanding about trading are of course different from gambling as you have said.