MDS, every comment I see, partner, when you convert you pay more, it's not the same sales value, and the fee is also higher, just pay attention, there it shows ALL the values

Can someone give a little help to a beginner here? Instead of buying and selling, I'm just converting. It's the same thing, right? Yesterday I lost a lot with $TRUMP . So every time it goes down I convert my reais into it and when it goes up, I convert it into reais again. Is that right?