stable coin guarantee is indeed quite difficult to understand. However, as a bounty hunter, there are many choices of coins. Can be used as a lot of opportunities. But you still have to be vigilant and careful in choosing, without promotion, in my opinion, it will not be as popular as a promotion.
It is not a Pandora box to understand the basic of a stable coin, they keep the equivalent amount as collateral either in fiat or other asset and there you have a stable coin but demanding those as bounty you are not going to get especially if you are joining any token projects bounty as they want to promote their project rather than giving you a stable coin 
.Project developers hire the bounty hunters first and foremost to work. And the work should be paid well, and not last, when the tokens will already be sold out by anyone and anyone. In this case, bounty hunters will not earn anything.