BitMEX is a centralized, custodial exchange. They also have a research arm that publishes reports like this.

Bitmex started as a innovative exchange that allowed ppl to deposit btc and speculate on btcusd price with high leverage and good ux. Meaning you made more btc :) or lost btc. It was very popular AFAIK. It was also no kyc. But things have changed a bit :) today we take for granted the perpetual contract they pioneered and every exchange has one it seems and also allow to use btc as collateral. But once upon a time bitmex was the first and only ones that did that :p