Read CfB's comments in context with the logic.

i) CMC doesn't include trading on the three decentralised exchange platforms Nxt has: Asset Exchange, Marketplace and Monetary System (and multigateway too, thinking of it. Though it isn't a core feature of Nxt).

ii) "Once everyone start using solely NXT its market cap will become 0, because no trades will be happening on centralized fiat exchanges" and centralized fiat exchanges are the only thing CMC reports.


The more Nxt moves to decentralised exchanges, the closer it will get to 0 on CMC as they only report centralised exchange stats. The decentralised stats are on the blockchain, but they just don't bother.