Good question. If you have an accepted purchase agreement and are closing within 60 days, you will have an option to lock in the rate or do not lock the rate “float”. Lock agreements are binding between the lender and the borrower so if you lock in the rate and rates goes down, you are not entitled to the new rate. Generally speaking, most purchase transactions will close within a 30 to 60 day time frame which is not that much time to ride interest rate cycles. Perhaps a best case scenario would have rates fall .25% in this period if time which would lower the principal and interst payment on a $150,000 mortgage approximately $22.00 per month, so it may not be worth the risk to you especially if rates increased. Interest rates are at historic lows, but how long we can expect them to stay at these levels no one knows, but rates tend to move upward faster than move downward.