I don't think if there is a way to prove this because this two are one of the dominating business now that people are doing everyday, so actually on this case we can only choose based on what we are currently doing, for instance since you are a forex trader and that's what you only do, you cannot choose to own a gambling if you are ask to peak between them and the same thing goes to someone who gamble they cannot prefer forex over something they actually no and love so actually the both of them generate a lot of money to there owners so I believe that's the only important thing and not actually the one that's better in bringing funds.