I only have experience with Agora and then Abraxas. When Agora was having problems months ago the word was exit scam, which proved to be false, right? I don't know the ins and outs of running a market place but it seems to be more profitable to run the market, and collect your fees, as opposed to taking a lump sum in an exit scam.
Evolution was the last big market that was confirmed to exit scam. I wonder what Kimble and Verto are up to these days.
Blackbank and Sheep disappeared too.