The oldest and first one to invent Proof-of-Stake is the most profitable (Peercoin). At least if you want your profits to be real and not made up of some dubious project that will suddenly run away with all your money.
The good old Peercoin may be worth the investment for the long term. It has been the first PoS coin in existence, with a well-established ecosystem of nodes and stakers. With this in mind, it could prove to become the most secure PoS coin in existence, making it ideal for staking with confidence.
Being trusted for many years due to its underlying community and development team, it can continue to survive in the crypto market for many years to come. Thus, if you want to invest into PoS cryptocurrencies, Peercoin should be on the top of your list.
Things aside, other good coins to invest into are Blackcoin and Ethereum (which will switch to PoS soon). This last one can be a huge opportunity for anyone to make profit in the future as once it migrates to PoS, it could have a positive effect over its price.
Nevertheless, be sure to check out the crypto markets for PoS coin which have good trading volume to secure your investment for the long term. As long as a PoS coin is being traded on a market, it will continue to survive. Just my thoughts
