Your stock portfolio still holds no interest for Fannie Mae, the government-sponsored enterprise whose rules may determine whether a lender will front you the money for a house. It will, however, take a peek into your crypto wallet if you want. In March, Fannie said it would begin accepting crypto-backed mortgages through a new product offered by Coinbase and Better Home and Finance. The move marks a major shift: While Fannie supports about 40% …