Nonsense, you calculated it by percentage, but the exchange calculates the percentage by points.

Shorting is always more costly than going long. With 100 dollars, it can at most drop to 99.99, leaving at least 0.01, but when it rises, it's different; it's like you don't know how high the sky is. It can rise several times, while falling can only earn you 99%, and it will never double. Some people say you can roll over your positions, but if it rebounds once, your short position can go to zero. Going long never fears a drop, but with shorting, as soon as it rises a little, it feels like it's about to skyrocket. 😀