You said it yourself already, that in order to do that, Nash needs a security license.
That won’t happen any time soon, being realistic. We could talk years.
However, nash is one of the few candidates that CAN get it, because recent sec statements have said they favor non-custodial exchanges.
That, together with KYC and trying to list tokens very carefully is quite a good sign. That doesn’t take away that basicly no crypto exchange has a security license, unless you count those who dealt with stocks and now deal with crypto.
Thus, it’s probably safe to assume that nash won’t be trading security’s (and therefore NEX) in 2020.