One great reason to HODL Monero too is that Monero's codebase is 100% independent of Bitcoin's codebase
If someone finds a huge bug in bitcoins code, it could affect a lot of other coins. But since Monero is a Cryptonote coin, it would not be affected.
And while one might say that Monero is more risky because the code hasn’t been used as much, there has been a lot of time gone into researching the code and making sure it is solid. (Because for those who don’t know, cryptonote is what Monero is derived from, but it was not created by Monero developers)
you would think that by this time if there was a major flaw in btc code, it would have been found, but sometimes it just takes a long time before the vulnerability is discovered.
Also a lot of the coins that have been coming out this past year are Ethereum based tokens, so that is something different although when you take into account the DAO, Multisig wallet hack and just the whole design of Ethereum its hard to call it well tested and secure compared to cryptonote and Bitcoin.
Monero's codebase isn't as obscure as most people thing. It's true that it's code is independent from Bitcoin, but it's base functionality is very similar. It doesn't use any kind of crazy new cryptography to ensure anonymity. It uses the safe and tested methods used by Bitcoin twisted in a way that can't really go wrong. Bitcoin is not fungible. Monero is the only fungible coin with an audit able supply, period.