excellent, had not heard of this one yet. Yes, sure, it's a centralized exchange and many people poo poo that for legit reasons. However, I have yet to see a decentralized exchange that is nice to use and has volume. Perhaps someday.
I do like that an established stock exchange is getting into it as it will add credibility and additional adoption.
RE: Rock Token (RKT): Blockchain Exchange Built on Best Practices.