I think and make suggestions to you :
To exchange trade and make a profit, the first thing I think of is poloniex then bittrex. Two sites that I like, with Polo you can Margin, Bittrex it convenient to buy and sell.
Looks like our minds work in the same way when it comes to exchange sites! I also suggest poloneix as it is among the best crypto currency exchanges. Bittrex is the second option but Coinbase and Kraken can also be given a thought. Poloneix daily bitcoin volume is somewhere around 45 million dollars so you can rely on it.
Of course, our thinking is never like the old ones that are happening in the market. The market is a dynamic chain of supply-demand. Here, its move is to gather everyone's thoughts.