From what I know the max supply will be 500 000 000  but at the moment its somewhere around 15 000 000. Some people think the coin will hit max supply by the end of the year, its 2 months old coin, so they are currently still working on a lot of things. This is definitely one of my favorite coins.
the staking is amazing and most of the people who buy this coin just stake it. I usually get 1-3% daily but sometimes I get even 10% ( WHICH IS AMAZING)
People who stake the coin will keep on getting this 1-3% ( or more ) until they hit max supply. They say that in case they hit max supply too fast, they could create a fork, we will see I guess.