Use your data in Example 8.4 to explore the time value of the option. Graph the price of the SPI call option against maturity. Notice how the time value diminishes more rapidly, the closer you get to option maturity. (In hedging their portfolios, fund managers sometimes buy options on the SPI when they are worried about some forthcoming event, relying on keeping options costs down by selling the option in the near future before the time value starts decaying on them.)