First it is important to make sure you only join bounties for good projects. You need to research them before joining to make sure they are worthwhile.
Secondly, prices for new coins often dump quite hard, but this isn't a reflection on the worth of the project itself, it's just a kind of self-fulfilling situation where people think the price will tank, sot ehy sell immediately, which causes the price to tank. It doesn't reflect on the project. For new projects you may need to wait quite a while to have an idea of whether or not they are doing well.