The 30 year fixed jumbo mortgage dropped to 3.125 percent this week with zero points at Bank of America, according to Corey Wilson, senior lending officer in Walnut Creek. This rate is with 20 percent down and a 780 credit score. Refinance rates are slightly higher. Nonetheless, the rates are excellent if you are considering buying or refinancing. B of A is closing escrows in 25 days with local processing and underwriting, Wilson said.