I think all of this can be profitable but having a difference from the highest level of risk is gambling because when you lose you will lose your assets, you better trade and become a campaign participant and if you can assemble and run mining tools.
For Gambling, mining, trading we need to have money in order to make money but one thing i can assure you if you start working campaign there is no need for any money, after getting some money you can start working on trading, Mining because gambling is very risky one.