So my net worth is 6 times what I would be looking to spend on a house, but banks still want to charge me 3.5% for a 15 year fixed. WTF? It's basically zero risk. Can't I get a full recourse mortgage, collateralized by my IB account that's worth a lot more than the house, for a much lower interest rate? And why don't they charge much lower interest rates for 40% down than for 20% down, since probability of the bank losing anything is much lower even if the housing market crashes and it goes to foreclosure.