Nowadays there are lots of projects where you can get the passive profit starting from nearly 5% per month, but to buy Nexo spending 18,5k and to hold them in order to get the 20$ as a result is really silly, may be just for fun.
$20 figure is just a guesstimate from............ "someone", no source. Take it with a pinch of salt...
And wait for the official announcement from NEXO.