It is because Bitcoin price is getting lowered gradually and the trades on Bitmex is made on the basis of the value of Bitcoin.

When Bitcoin’s price was 20k, if you had 1 bitcoin, you could make order worth 20k on Bitmex using 1x leverage.

But now, you can only make order worth 3k dollar with 1 bitcoin using 1x leverage.

This is what happened to all traders on bitmex and this is natural phenomenon.

I think you can understand my words if you understand how the margin trades is made on bitmex.

It is not the cause of the drop of bitcoin price but the result of the drop of bitcoin price.

Sorry for weird English
I’m not a native speaker