gambleˈɡamb(ə)l/verbgerund or present participle: gambling
play games of chance for money; bet."he gambles on football"synonyms:bet, wager, place a bet, lay a bet, stake money on something, back the horses, try one's luck on the horses; More
take risky action in the hope of a desired result."he was gambling on the success of his satellite TV channel"synonyms:take a chance, take a risk, take a leap in the dark, leave things to chance, speculate, venture, buy a pig in a poke; More
Seems like gambling to me.
Oh if only the world were as simple as being able to fit neatly into little placeholders like dictionary definitions.
No one said investing is without risk, but you're taking one definition of gambling and using it to fit your idea of what investing is. A = B and C = B, therefore A = C is not correct logic.