Probably obvious to most of you but I didn't really feel it until I looked at one trade from my practice log...
Put up $7,871 margin at 40x so the position was $314,822. trade made +$527 gross, fees and funding were -$132, net +$396
A Quarter of the profit gone and that was a WINNER. fee was around 0.04% of the position which sounds like nothing but at 40x thats ~1.7% of your margin per round trip
Rough way I think about it now is round trip cost as % of margin is about fee rate x 2 x leverage
So at 0.04% per side youre paying 0.8% of margin at 10x, 2% at 25x, 4% at 50x. and thats before funding. every trade has to clear that before it makes you anything
Across all 579 of my practice trades fees added up to $7,187, which is more than half my total net loss (-$13,887). Not the main reason I was red, that was liquidations, but still a big chunk
Stuff that helped me was taking fewer trades i actually believed in instead of tons of small scalps, lower leverage (same idea smaller position = cheaper in and out), limit orders when i can since maker is usually cheaper, and keeping an eye on funding if i hold overnight
Anyone else get surprised when they actually add up their fees?