The rate of interest to be paid on a note secured by real property is linked to fluctuations in the market rate of interest. With such a mortgage, a lender need not be concerned about rising interest rates if due-on-sale clauses are unenforceable because it can charge, within limits specified in the adjustable rate mortgage, the same interest on the existing loan, assumed by a buyer of real property, that it could charge on a new loan it could otherwise make with the money collected from enforcement of a due-on-sale clause.

     While adjustable rate mortgages became less important to lenders following legislation which made due-on-sale clauses enforceable, the device had by then become attractive to borrowers and an established part of the market for money.   Thus, instead of disappearing, the development of adjustable rate mortgages in turn inspired legislation, including truth in lending disclosure legislation, designed to protect consumer borrowers against unexpected surprises from their adjustable rate mortages.