Have to be honest, I have a small portion of my portfolio (1-3%) in Bitcoin simply as a hedge against inflation. It's neither speculative nor novelty and has replaced a portion of what would typically be bond holdings. It seems companies and major asset holders are now considering the same.
I started like that, then it jumped, I recovered my cost basis plus expected inflation for years and taxes, and now it's more like 8/10% of my portfolio but I'm not touching it and I'll just see what happens. It was "free money" after all.
It's the second time I'm doing this, the first time I had to spend the money on moving but those were mostly mined coins.
