I can assure you that good traders know what they are doing and manage their way to success, unlike gambling, which is highly luck-based. It's basically betting.
How you can be sure that trading is different than gambling

, trading itself is highly luck based, you can't predict current war that caused market to dump so hard, if you do you would've shorted it.
You can try technical analysis but most of them are self fulfilling prophecy, at most they increase odd from 0.50 to 0.51. In literal sense both are the same speculation on probability.
Except trader just want to be recognized differently

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They are similar but I don't think there is any significant difference just that even with luck you will still need to do some analysis just to be sure of what you are doing exactly and there are different reasons why trading is more advance than gambling and people always have the mindset of coming and the next thing they are making money and before you start making money from gambling you have to do a lot of study. And also be consistent because without consistency you will eventually give up because there are traders that just because they have failed they think there is nothing there for them but gambling is actually more than that.
There people that are making money from it so what makes it different the only thing is that follow the process and when you do so I don't think there will be any challenge.