how does one know if he really paid a fair price, even if good relative to mid, on an illiquid perp, where the underlying is closed? you're just paying whatever the market says is fair at that time, not the actual fair, even if your execution was great.
what I mean is, if I know btc is worth 90k today at major exchanges, and I pay 90k for it, I know I got a mid deal (pun intended) for it.
but if I'm trading AAPL perp and AAPL is not open like if it's weekend, and you're trying to get a good fill, you might get a good price relative to mid at that time, but that mid is irrelevant in the whole "