@haejin, I am with you. Recently I've had problems with Bittrex, and I had 100 tokens floating on the Bittrex exchange for no real reason. It took 3 days to resolve. It was a bit unsettling to have tokens confirmed in my local wallet but not on Bittex. I had used that address successfully before, so there was previous success, should have been no real issue. Then, yesterday the news of Bittex shutting down people's accounts. I don't believe in coincidence. Something is up. A decentralized exchange is the wise route, and my thoughts are etherdelta and BTS.