Template:M summ GMRA 2(pp)

So the price at which you buy the bonds back is the price at which you bought them (the Purchase Price), plus the time value of your trade. Thus, the Seller in a repurchase Transaction retains the price risk of the bonds. If she sells at 100, for a month, with a Pricing Rate of 10% — bear with me: these numbers are not meant to sound realistic but to accommodate the JC’s well-documented struggles with arithmetic — then the Repurchase Price at the end of that month will be 100 + (10 * 30/360) = 100.833.

The Seller must repurchase the bond for 10.833 regardless of the market price at which the bond is trading at the time. Thus the bond functions like collateral for a loan of cash, which must be repaid with interest. Should the bond move in value against the cash repayment obligation, the Margin Maintenance provisions kick in to allow the parties, as they wish, to call for margin.