The theoretical price of the following future with the previous example, suppose that you buy a contract for the future by which you, who believes that the price of the car is going to place above 10.518 euros, acquires the obligation of buying that car at that price fixed (10.518) within a year, knowing that the price of the car is today 9.015 euros. What is based on you to estimate that the price of that car will vary in 1,503 euros over a period of a year? There any way to estimate or calculate a price that serves as reference to find out if the price of a future is overvalued or undervalued? This reference price is known as the theoretical price of the future. To see more clearly, take as a reference an action of a particular asset. Suppose that such an action is trading today at a price of 22 euros. How much will be worth such action within a year? Or what is the same, what would a theoretical value within a year? The difference between the price of the stock within a year and the current price of the stock is called net cost of financing or cost of carry. The net cost of financing or cost of carry is the cost of financing less yield from dividends of that asset. The net cost of financing can be positive or negative, depending on whether by dividend yield is less than or greater than the cost of financing. The theoretical price of the future will respond, therefore the following formula: theoretical future price = price x current (1-airfare) d; where t = time on which we are calculating the theoretical price of the future expressed in years; i = risk-free rate, expressed as a 1; d = cash dividend rate until maturity (profitability cash dividend).
Take, for example, the described action previously trading today to 22 euros. Suppose we want to calculate the theoretical price of the future within six months (180 days), with a 2.5% risk-free rate and paying a dividend until the day of expiration of 0.50 euros.
