I guess you want to dump bounty token  . well if it is in this case you have no option than to use the exchange that the token you are holding is being listed. many ICO nowadays are either locking their token for a specific period of time just to prevent dumping of their asset or they may not list the token on any exchange until a long period of time but in case you are holding a token that is listed in more than one exchange platform, you can try and check the market volume of the coin in both exchanges, compare the price. Probably the one with higher token volume should be your choice.