Subprime lending refers to the extension of credit to higher-risk borrowers, a practice also commonly referred to as "B/C" or "nonconforming" credit. Loans to subprime borrowers serve communities that may have been underserved by other lenders in the past. In recent years, subprime mortgage lending has grown dramatically, with over 90% of all subprime mortgage loans made in or after 1993. By the end of 1996, the total value of outstanding subprime mortgage loans exceeded $350 billion. In 1997 alone, subprime lenders originated over $125 billion in home equity loans. Subprime loans have become a significant and growing part of the home equity market. Subprime originations constituted 11.5% of the total home equity lending market in 1996; by the first half of 1997, they had grown to 15.5% of this market. At the same time, the composition of companies involved in the subprime market is evolving. One of the dramatic changes in this market has been the growth in subprime mortgage lending by large corporations that operate nationwide.

The subprime mortgage market has flourished because such lending has been profitable, demand from borrowers has increased, and secondary market opportunities are growing. Lenders typically price subprime loans to consumers at rates of interest and fees higher than conventional loans. Higher rates and points can be appropriate where greater credit risks are involved, as is often the case with subprime loans. Critics assert, however, that the interest rates and fees charged by some subprime lenders are excessive, and much higher than necessary to cover increased risks, particularly since these loans are secured by the value of a home. Some attribute lenders' high rates on first mortgages in part to federal deregulation of certain state interest rate ceilings in 1980.

The relatively high profit margins in the subprime mortgage industry have fueled demand in the secondary market from investors seeking higher-yielding securitized assets, especially in an environment of generally low interest rates. In 1996, the subprime mortgage sector issued over $38 billion in securities, the largest increase in securitizations for any lending industry sector in that year. The secondary market's expansion has, in turn, helped to sustain growth in the industry by enabling lenders to raise funds on the open market to expand their subprime lending activities. Freddie Mac, one of the primary government-sponsored enterprises involved in the purchase of mortgages, recently announced plans to enter the secondary market in subprime loans by purchasing significant numbers of "A minus" subprime mortgages by 1998 and the higher-risk "B and C" loans by 1999.

The market for subprime loans is expected to continue growing. Credit card delinquencies are rising and personal bankruptcies are at record levels, which negatively affect borrowers' credit histories, pushing more consumers into higher risk categories. Meanwhile, consumer spending continues to be strong. Together, these factors increase the market for subprime loans. In addition, more borrowers generally may be seeking home equity loans due to the change in the tax code limiting allowable interest deductions to those on a first mortgage.