Since you are looking for a relatively safe investment, why not choose BTC directly, I don't think there are any coins that are safer than BTC. Why are you using Altcoin? Do you think this can bring you more profit? But in fact, I don't think so. Since you want to be safe, it must be coins that are less variable, that is, coins that make it less likely that you will double your investment. In this case, bitcoin is your best choice.