A market-indexed mortgage system and method are provided that enable one or more borrowers to finance or refinance a real estate property and have at least a portion of the payments indexed to local relevant real estate values. The mortgage loan provides upfront liquidity to purchase or refinance the property; the borrower has payment stream going back to a lender (or holder of the note) wherein one or more payments are adjusted or determined based on the index. Such market-based mortgage loans can be pooled in a fund and fund shares can be issued against the fund. The mortgage can be a residential mortgage in which the regular (e.g. Monthly) payments (interest and or principal) fluctuate with a price index for the local house market. Balance upon prepayment can also fluctuate with such an index.