Provided is a computer-implemented method for providing a common index securities fund that provides liquidity in a plurality of small business borrowers in a defined class. The method comprises providing a pool of cash from a lender to the fund; generating loans from the fund to borrowers; depositing the loans in interest-bearing accounts; providing interest from the interest bearing accounts to the lender and the borrowers; and, upon withdrawal of the loans from the interest-bearing accounts, repaying the loans to the lender and commencing a payment stream by each borrower to the fund, including adjusting one or more payments in the payment stream using an index having a value relationship to the class.