https://republicprotocol.com/
"Decentralized dark pool exchange protocol. Built for laundering large volumes of crypto."
https://www.fincen.gov/news/news-releases/fincen-fines-btc-e...
They look pretty legit. Here's more info:
https://venturebeat.com/2018/09/27/worlds-first-decentralize...
It's worth noting that I've no connection to them nor any conflict of interest, just thought it was topical. Didn't have time to make a disclaimer in my original post.
https://republicprotocol.com/