The OILspace Options Calculator uses the Binomial Tree Model to calculate the value of options prices. The Binomial tree Option Pricing method assumes that the price of the underlying can go up or down by fixed multiples. Each price jump is assigned a probability and a tree of possible underlying prices is built. Working from the tree points or nodes at the option maturity date, the worth of the option can be back calculated until the option can be valued at the desired date.