In the words of Warren Buffett, it's called "the greater fool business model" and it's the belief that a greater fool will come along and pay you more than you paid.
That doesn't exactly apply here. It's not about whether or not some fool will come along and buy something you purchased for more money than you paid - it's about believing the value will rise naturally due to speculation + adoption + technical advancements (in cases like IOT data monetization). It's a high risk + high reward investment, and you need to go into it understanding that you could very easily loose your entire investment. If you are young, it probably makes sense to put a small percentage of your portfolio into crypto, but don't be stupid about it. 5% of my portfolio is currently in crypto, and as a strong believer in DLT + potential to disrupt many industries, I'm using this bear market to increase that percentage through dollar cost averaging (buying small amounts each month).
You had mail, but the super-user read it, and deleted it!