A computational tool leverages a discrete-time framework to determine the theoretical value of an option. This framework divides the option’s life into a series of time steps. At each step, the model assumes the underlying asset price can move either up or down by a specific factor. By working backward from the option’s expiration date, calculating the payoffs at each node in this “tree” of possible price movements, and discounting those payoffs back to the present, the tool arrives at an option’s present value.
This approach offers several advantages. Its relative simplicity facilitates understanding of option pricing principles, even for those new to the subject. The method readily adapts to options with early exercise features, such as American-style options, which pose challenges for other valuation techniques. Historically, before widespread computational power, this model offered a tractable method for pricing options, paving the way for more complex models later. Its pedagogical value remains strong today.