What is the ROI on margin trading BTC or any other cryptocurrency for that matter?
This is a dangerous transaction and many people have committed suicide because of losses. This is a gambling game. This game is very popular but it will cause huge damage to your market and capital. When many bets are right, the whales will change the market in another direction so that they can make a profit.
Margin trading is far from gambling, I dont think using margin when you want to buy a commodity and no cash in stock to do so is gambling. Margin is being abused by people that make margin trading look like its gambling, they are the greedy ones trading without minimizing the risk involved and this makes margin trading a little more of a gamble because of the often increase in risk.
I will only agree that trading is gambling for those that does not know what they are doing, but generally speaking, you need leverage to enhance your gains and obviously it has its own risk levels. If you understand the risks and trade accordingly then margin trading must be a better way to make more profits for given capital amount.