All the coins are from the old chain. This is a swap. The POW/POS refers to how blocks are created not coins (this is true for any coin). All crypto coins will end up at this point (of no block reward). Having POS for block creation is more attractive than mining since it uses significantly less power. You only need to run your wallet with a sufficient balance and the network will function. Many people, including myself, run their computer 24/7. Adding a few POS wallets barely adds to my power use.