Have you ever invested in cryptocurrency?
I have never invested in cryptocurrency, but I have invested in a lot of things that could be considered "cryptocurrency," and it's been a pretty good investment.
If you're talking about crypto-currency as a type of currency that is stored digitally, then yes, I have invested in it. I've invested in the digital currency known as Netflix, which has increased its value since its inception by thousands of percent.
If you're talking about crypto-currency as a type of currency that can be traded on an exchange like stocks or bonds, then no, I haven't invested in it. But if someone was to offer me a piece of cake for free that had been baked with love using only natural ingredients and then sell me that same cake for $3… well… now we're getting into some serious crypto-currency territory here.