A tutorial on the determination of futures prices, including the spot-futures parity theorem and how prices conform to spot futures parity through the market arbitrage of futures contracts, and how parity affects the prices of different futures contracts on the same underlying asset but with different terms of maturity; illustrated with examples. Options Calculator. Our popular Options Calculator provides fair values and Greeks of any option using previous trading day prices. Customize and modify your input parameters (option style, price of the underlying instrument, strike, expiration, implied volatility, interest rate and dividends data) or enter a stock or options symbol and the database will populate the fields for you. Before you invest in futures contracts it is important to review these products with an investment professional. Using the Futures Contracts Calculator. If you've decided you want to add futures contracts to your portfolio, the Future Contracts Calculator will tell you how many to buy, based on the price, your tolerance for risk and the size of