I thought, that Waves could only be traded on Bittrex. But now I found, that there are two additional exchanges: Liqui and Hitbtc. Both are very small and the trade volume is very low, but better than nothing . Here is the complete list:

bittrex.com: https://bittrex.com/Market/Index?MarketName=BTC-WAVES (BTC vol. 1115)
liqui.io: https://liqui.io/#/exchange/WAVES_BTC (BTC vol. 23)
hitbtc.com: https://hitbtc.com/exchange/WAVES-to-BTC (BTC vol. 0.5)

Does anybody know other exchanges? Are there any news concerning getting listed on Poloniex or Kraken?