What makes the interest rates of these bank rate mortgages rise? What makes those of bank rate mortgages fall? These questions race through our minds whenever we are faced with a financial situation that requires us to understand a little bit more about bank rate mortgages. The answer is simple enough. Reducing even a fraction of your mortgage interest rates can save you a great deal of money on your mortgage. The rise and fall of mortgage interest rates have become erratic during the past 20 years. As a rule of thumb, mortgage interest rates go up when the economy is strong and stock prices rise. On the other hand, if economy weakens, mortgage interest rates go down. Because the interest of a 30-year fixed rate mortgage is amortized over a longer period, the monthly payments for this are lower than those on 15-year loans. Lower monthly payments on 30-year fixed rate mortgages give consumers an extra resource which they can pour into other worthy investments. On the other hand, this could also cause a slight disadvantage for 30-year fixed rate mortgage borrowers. This means that the 80 20 mortgage loan has a fixed rate for the first five years. However after the initial five years, the payment for the 80 20 mortgage loan interest rates is adjusted annually. Others structure their 80 20 mortgage loans in a slight different way. 80 20 mortgage loans have the 20 percent piggyback dependent on the prime rate. To explain further on this, let's say you have a balloon payment mortgage with an interest rate of 7.5%. After seven years, an approximate 92% of the original balloon payment mortgage amount is due. For example, the amount of the balloon payment mortgage is $200,000. The interest rate for this balloon payment mortgage is 7.5%. Also, adjustable rate home mortgage rates are short-term interest rates like Treasury bill rates. If you're planning to keep your home for only a short period of time, then an adjustable rate mortgage might be the best choice for you. Adjustable rate home mortgage rates are significantly lower than fixed rates, especially during the initial years of the loan term.