Nerva has been listed on TradeOgre exchange since 2018. Up to this point, it has been listed under BTC pair only. TradeOgre just added Nerva to USDT pair so now traders can trade it for Bitcoin and Tether.
Here are direct links to both trading pairs:
XNV-USDT trading pair on TradeOgre:
https://tradeogre.com/exchange/XNV-USDT
XNV-BTC trading pair on TradeOgre:
https://tradeogre.com/exchange/XNV-BTC