MARGIN

  1. Money borrowed from a brokerage firm to purchase securities; the practice is called buying a margin
  2. The amount of equity a customer contributed as a percentage of the present market value of the securities in a margin account
  3. In business, the difference between the price of a product or service and the production cost
  4. Part of the interest rate on an adjustable-rate mortgage, which is over and above the adjustment-index rate