I exchange mine in ether delta. I trade multiple of times with the gas of 4 and a lot of my transaction is just seconds to send and receive .. same as mine I dont know why but it is pending.. maybe the man dont have enough balance to cover the payment for my token haha or the balance left was not enough to pay the fee..
I think that is the main thing why it is pending. Now I am waiting for the confirmation because I cant create a new transaction with that pending transaction