a spread over the prime rate, the securities created are based on a spread over 1-month LIBOR. Exhibit 10.9 presents a Bloomberg Security Description screen of a HELOC floating-rate tranche issued from the Advanta Revolving Home Equity Loan Trust, Series 2000-A. This floater has a coupon formula of 1-month LIBOR plus 25 basis points with a floor of 25 basis points. The coupon payments are delivered and reset monthly. Because HELOCs are for revolving lines, the deal structures are quite different for HELOCs and closed-end HELs. As with other ABS involv- ing revolving credit lines such as credit card deals, there is a revolving period, an amortization period, and a rapid amortization period.   Manufactured Housing-Backed Securities Manufactured housing-backed securities are backed by loans for manu- factured homes. In contrast to site-built homes, manufactured homes are built at a factory and then transported to a manufactured home community or private land. The loan may be either a mortgage loan (for both the land and the home) or a consumer retail installment loan.     Manufactured housing-backed securities are issued by Ginnie Mae and private entities. The former securities are guaranteed by the full faith and credit of the U.S. government. Loans not backed by the FHA or VA are called conventional loans. Manufactured housing-backed securities that are backed by such loans are called conventional manu- factured housing-backed securities. The typical loan for a manufactured home is 15 to 20 years. The loan repayment is structured to fully amortize the amount borrowed. Therefore, as with residential mortgage loans and HELs, the cash flow consists of net interest, regularly scheduled principal, and prepayments. However, prepayments are more stable for manufactured housing- backed securities because they are not sensitive to refinancing. There are several reasons for this. First, the loan balances are typically small so that there is no significant dollar savings from refinancing. Second, the rate of depreciation of manufactured homes may be such that in the earlier years depreciation is greater than the amount of the loan paid off. This makes it difficult to refinance the loan. Finally, typically borrowers are of lower credit quality and therefore find it difficult to obtain funds to refi- nance. As with residential mortgage loans and HELs, prepayments on man- ufactured housing-backed securities are measured in terms of CPR. The payment structure is the same as with nonagency mortgage- backed securities and home equity loan-backed securities. As an illustration, Exhibit 10.10 presents a Bloomberg screen of