Those looking for a North Florida mortgage may consider an adjustable-rate mortgage. It has three primary components: an index, margin, and calculated interest rate.  The interest rate is based on an index that measures the lender’s ability to borrow money. The specific index used may differ depending on the lender. The index cannot be controlled by the lender.  The margin, also referred to as the spread, is a percentage added to the index in order to cover the lender’s profit and administrative costs. The index may rise or fall, but the margin typically remains constant over the life of the loan. The calculated interest rate and margin added together, you arrive at the calculated interest rate, or the rate the homeowner pays. It is also the rate to which any future rate adjustments will apply. When seeking a Jacksonville Florida loan ask a professional for guidance.