Hunters sell because need money. That's the main reason, or else there's a second reason, it is not the most promising project, then also better to sell. I would advise all your rewards not to sell, bring only the necessary funds, and the rest to invest in more reliable coins or leave new coins in the hope that they will grow. But it all depends on the specific situation, you have to decide for himself.
Bounty hunter sell their receive reward immediately, for me there's a lot factor why they sell it, example of that is the value of token is higher. Second they think has o potential so selling it immediately is the good thing to do, third they have most reliable other token to hold so they sell it. Forth they need money immediately. Selling the receive token is depend what the situation, like if the market is rapidly growing then its better to sell but if not its better to hold.
