Binomial Model

AdvancedOptions & Derivatives1 min read

Quick Definition

An options pricing model that uses a discrete-time tree of possible price paths to value options, especially useful for American-style options.

What Is Binomial Model?

The binomial options pricing model, developed by Cox, Ross, and Rubinstein in 1979, values options by constructing a recombining tree of possible future stock prices. At each time step, the underlying price can move up or down by a specific factor, creating a lattice of possible outcomes. The model works backward from expiration, calculating option values at each node based on risk-neutral probabilities. Its key advantage over Black-Scholes is the ability to handle American-style options with early exercise features, discrete dividends, and changing volatility. As the number of time steps increases, the binomial model converges to the Black-Scholes price for European options. The model is intuitive, flexible, and widely used in practice for pricing complex derivatives.

Binomial Model Example

  • 1Using a 100-step binomial tree, a trader prices an American put option on a dividend-paying stock, finding the optimal early exercise boundary at each node
  • 2The binomial model shows that an American call on a non-dividend stock should never be exercised early, confirming the theoretical result