I've got a few coins on the side and I'd like to make them work.
Which gambling site do you advise me to invest in the bankroll?
Mining got even higher risk because it may take many months to recover back your investments and it is not suitable for many developed countries to reason their electricity charges are higher than what they can earn from mining. Investing in casino bankrolls are high risk but if you do a proper diversification then you can make a good profit in the longer run.
That is correct. Mining nowadays is not so worth at least in my country because as you said electrical charges very high so it is not economical to try mining. But both trading and investing in casinos are good to explore. I don't suggest you go for day trading because you may lose your investments faster than expected so always just buy good coins and hold to sell at higher prices.
Mining is very different because you are actually buying hardware so its not quite the same as an investment where you just buy it and forget about it. You need to physically have the hardware and support it.
Mining used to be OK but with the recent surge of Ethereum price its basically very difficult to get started because you can't even buy any of the hardware. Most of the motherboards which support 6+ GPUs are out of stock, many of the 6+ GPU motherboards can only run 4 GPU. Also many large PSUs are out of stock or oversold. And last but not least are the impossible to find GPUs. Even if you find some in stock they are very badly overpriced.