I suspect that the people who would take out a mortgage to invest in Cryptocurrency are in that hopefully small subset of the population that is going to make some kind of catastrophically bad personal financial decision at some point anyway. Using Cryptocurrency as collateral in loans though does seem interesting. I wonder how people are doing the risk analysis on that. Personally, I'm not a fan of Cryptocurrency. It's no longer a practical currency and won't be again until it stabilizes. So people are apparently seeing its use as a store of value, which I'm not seeing.