The dude is in net profit from trading, he only used a much higher leverage on that trade and somewhat got liquidated.
A rich person like him suppose not use leverage at all which is the reason he lost so much. Using millions to trade can give high ROI without using leverage but I do not know the reason he is using high leverage to trade which is just greediness and he got liquidated. If he is not careful, he may later go broke or he should just change.
Maybe because there is the option for leverage, there is the thought that it must be used.
I had same reasoning thinking from the side of someone with limited capital for trading the importance of Leverage, but reading this your statement, I understand that the trading conditions can be different for someone who has a large capital, Leverage can be unnecessary. Thank you for this.