Is the crypto you're currently HODLing based on Proof Of Work? If yes, you might want to know some potential attack vectors (based on true stories!) and the reason why PoW, after all these years, might not be the solution after all.
PoW is the Steam Engine of decentralization, and it's about time to look forward and see what alternatives are there - efficient and rewarding ones.
More resources:
Relax, your bitcoin are safe. Or are they?
https://medium.com/@capodieci/advancing-in-blockchain-technology-26881e8e6e71
Proof of Work is dead
https://medium.com/@capodieci/advancing-in-blockchain-technology-part-2-of-4-d5396e46be3
Why Proof of Work Is a Wrong Method to Secure Blockchain
https://youtu.be/0sDtorfzG7w