MiamiCoin and NYCCoin can no longer be traded on their main cryptocurrency exchange after a period of exceptionally low liquidity.

Miami is spending millions on a new rental assistance program, but the funding source, MiamiCoin, is only vaguely understood by city leaders.

Austin, Texas, could become the third city with its own cryptocurrency, but officials there said they're still researching the technology.

CityCoins founder Patrick Stanley said he's planning to expand to new locations.