Abstract: A system comprises a memory operable to store a first closing value of an index for a first day, wherein the index is based at least in part on a cash account and a variance future. The system further comprises a processor communicatively coupled to the memory and operable to determine a first settlement value of a variance future for the first day and to determine a second settlement value of the variance future for a second day. The processor is further operable to determine an increase of cash in the cash account from the first day to the second day, wherein the determination is based at least in part on an interest rate. The processor is further operable to determine a second closing value of the index for the second day, wherein the determination is based at least in part on the determined increase of cash in the cash account, the first settlement value, and the second settlement value. The processor is further operable to store the second closing value in the memory.