Have you checked out x42 Protocol? It is by far one of the most underpriced coins in the world! They are a proof of stake, feeless and almost instant coin that supports their own version of masternodes (called xServer, which is a platform that allows for decentralization of any type of application) and an amazing wallet called xCore (you can run decentralized applications from the servers in it!).
The staking rewards on x42 will last for over two decades, so you can get passive income for a very long time for almost very cheap right now!
You've missed making a fortune with bitcoin, are you going to do that again?
x42 has been around since 2018 and it is considered one of the most actively developed cryptocurrencies in the space, one only has to check their discord to see that: https://discord.gg/hjmjs23
You can get x42 Protocol at three exchanges right now:
https://app.stex.com/en/basic-trade/pair/BTC/X42 (KYC needed)
https://graviex.net/markets/x42btc
https://altmarkets.io/trading/x42btc#
Don't take my word for it, read their whitepaper, check their work, these guys have been doing a lot in silence, but that won't last for very long.
Whitepaper - https://x42.tech/whitepaper.html