I would NOT recommend Poloniex. They tend to freeze funds(ESPECIALLY STEEM) during times when the price is pumping and not see those funds until days, weeks, or even months later as I did.
https://cointelegraph.com/news/poloniex-crypto-exchange-users-can-now-use-cards-and-bank-accounts
You got a 5.35% upvote from @minnowvotes courtesy of @zapper!