My experience tells me that sometimes to sell bounty rewards as soon as it hit the exchange may be a good decision. I have noticed some bounty posters who have complained of not making profit from the rewards after they left it believing it will increase and some reduce to nothing after a while. For me I decide not to regret when I take decision to sell.
Depends on the bounty reward obtained. If the bounty reward is in the form of a project token that is still not listed anywhere, then there is no other way but to hold it until it is listed on an exchange or Dex. But if the bounty rewards are in the form of coins that have been registered such as Bitcoin, ETH or other coins the decision to sell is a pretty good decision. But if you still believe the price will go up, then wait and hold for the long term. it's a personal choice to hold or sell.