But i lost 400$ in last month due to trading

So , i think this has low risk than that
Trading requires patience and technique, because if you don't have the patience and technique, then you will always lose, so try to go a very simple way by buying USDT when the tokens are already at a high price, because USDT tokens tend to fall the price is a little bit when other tokens increase in price, and vice versa, USDT will experience a slight increase when other tokens experience a price correction, this will give you an advantage and can save your assets too, and one more thing, when you are already selling USDT tokens that you have bought, you can also net other good tokens at a low price even slightly lower than the Low price seen in the market, this is a very simple way, hope it can help you.
