I would suggest you to invest a significant amount in Monero and to stop investing in Bitcoin Cash. They were a fork of bitcoin and has received significant hate among the bitcoiners.
That hate doesn't mean it's a bad coin or that it's going to underperform anything else in the long term, which is probably op's timeframe. Bch has done fairly well since it was released. A *lot* better than any other of the forks I know of that came out around the same time, anyway.
Can you hold any crypto in an IRA? I never saw the purpose of doing this except for tax purposes, and I guess if you don't mind everybody knowing that you own crypto it's all fine and dandy. If you can keep altcoins in your account, I'd probably agree with HH about monero. I think it's one of the few coins that's escaped the attention of investors and it's a good one. You're probably not looking for the anonymity it provides, but it's still a good coin and should increase in value over time.