As what most successful investors say:
Don't invest what you can't afford to lose.
Since Bitcoin and other cryptocurrencies have their own levels of volatility, it is best that you diversity. Diversification helps mitigate volatility, especially in long-term investments. It averages out your gains and your losses. I ot a lot of great tips here: https://coincentral.com/the-bitcoin-stock-debate-practical-investment-advice-for-the-long-term-investor/