Consider a two-step binomial tree. A non-dividend paying stock price starts at $50, and, in each of the two time steps, the stock may go up by 20 percent or go down by 20 percent. Suppose that the risk-free rate is five percent per annum and that the time to maturity, T, is two years. We would like to find the value of a European put option with a strike price K of $52. The following diagram shows the pricing of the stock and the payoffs at the terminal nodes using a binomial tree:
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/ebfbaecf-a7a2-4763-bb3d-cf9673e98c4d.png)
Here, the nodes are calculated as follows:
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/56cb6902-2c50-4589-8d03-71981ff9cd15.png)
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/6c899404-b04e-4695-be22-8f1f4a46fac0.png)
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/70e15ac6-f601-410d-9371-32cfb0dbe24e.png)
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/6eda97f5-8781-4acf-9a3a-a88c41375fd5.png)
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/a959a1cf-4af3-4fba-904a-3e316030ad56.png)
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/98ee5ef1-3fa8-47fd-afd2-5fecdbe22756.png)
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/c7579cd4-bc65-439b-9657-25691097682c.png)
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/82886492-9cb6-4ebe-b4fc-40d5b97d7da3.png)
At the terminal nodes, the payoff from exercising a European call option is given as follows:
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/401d00a1-d6b5-4980-9cad-d589da05a7cf.png)
In the case of a European put option, the payoff is as follows:
![](https://static.packt-cdn.com/products/9781789346466/graphics/assets/91b879ad-9ac4-4540-b9a2-a9a9dbf3b42d.png)
European call and put options are usually denoted by lowercase letters, c and p, while American call and put options are usually denoted by uppercase...