Mortgage buyer chief Richard Syron tells shareholders the company's earnings will grow 15% to 20% this year, but not before taking $6 billion hit from bad mortgages. To make sure that you're getting the best rate available in the market, it is important that you also obtain all information on important costs involved. Getting the best mortgage rate is knowing how much of a down payment you can afford. Aside from that, getting the best mortgage rate is knowing what is the interest rate of your loan.