yes of course trading can be consider as high risk investment, i think it can really, although all investments are risky but gambling is a little more that any other investment.
Trading is indeed investment ( investing into something and selling at higher prices ) while gambling is totally a risky and luck based gaming that is done while you are in negative chances of winning, I would consider gambling as investment maybe if there was no house edge at all.
I see it as investing on yourself because you skills matters in trading, you will set a bankroll or capital and you need to manage that by predicting the price and if you are prediction is right most of the time that means you are good and your skills will make you rich.