The Big Short is a great, great movie.

It's technical but not impossible to understand, and it explains a major event in our lifetime - the 2008 financial crisis - in a way that's both humorous and serious.

The Big Short tells the story of a few outsiders that noticed that absolutely insanity of the mortgage industry in the US ahead of the collapse.

I'm mentioning this because Fannie Mae, the government-sponsored Federal National Mortgage Association in the US, is now accepting crypto-backed mortgages, as reported by the WSJ.

I love crypto, but that seems to be a bit dangerous.

Developed with Coinbase, the programme is simple: it allows you 'pledge' the assets (only BTC and USDC) to take a traditional mortgage.

I don't know that's a good idea, though.

USDC, I get it, maybe, but Bitcoin is very volatile, we all know that, and allowing people to take out a mortgage using BTC as collateral begs at least one question: what's the LTV? What's the loan-to-value?

With Nexo, you can do something vaguely similar, and the LTV is 50 percent for BTC, and the rate is insane.

Maybe that's their thinking.

But it still looks like history repeating itself.