Matt Levine wrote about this recently. In theory there's a win-win trade where you should be able to buy out your 3% mortgage at a discount (or equivalently, pa

Matt Levine wrote about this recently. In theory there's a win-win trade where you should be able to buy out your 3% mortgage at a discount (or equivalently, pay it off and get a mortgage on a new place at a slightly higher rate). In practice, banks won't do this because they figure you're bluffing and will eventually move anyway.