HitBTC has good volume for fiat pairs such as EOS/USDT, BCN/USDT, DOGE/USDT etc. with decent volume. Interestingly, they had STEEM/EURO pair with very low volume, now discontinued. They should have STEEM/USDT fair (i.e. I requested them several times and traded over there for 3 years). Unfortunately, STEEM/SBD withdrawal are disabled for months for unknown reasons, it would be great if devs or @zappl are in contact with them to solve the issues.

EDIT: I mine some BCN, I sell them for USDT at HitBTC, then buy DOGE, transfer to Poloniex to sell them to buy STEEM and transfer STEEM to my Steemit wallet. Exchanges has weird issues, I can't sell small amount of DOGE at Bittrex or depositing BCN to Poloniex takes 14 hours (In HitBTC 25 minutes). Once we have fiat pairs for STEEM, or simply STEEM/BTC pairs in top exchanges due to its fast confirmation, zero fee and scalability, it can can be the choice for the top transaction crypto for all kinds of arbitrages, then STEEM can see very large volume.