Good info, though your point on diversification is very dependent on a particular investors goals. Specifically in terms of volatility, not all investors are averse to it because of the risk. In fact, the market has been rather nonvolatile of late and that has it's own concerns. Low volatility may mean less risk, but it also means less reward.

Look at that scatter-plot for Bitcoin, the price in a given day is far more volatile and that is great for folks trading because it gives them many points to try to buy low and sell high. S&P 500, with it's overall far lower volatility, doesn't provide the same level of opportunity.

Your point about them not being correlated, however, is spot on and that bodes very well for diversification purposes. I am looking forward to my crypto-portfolio getting going!