How Expected Growth Enters Option Pricing Through the Stock Price

Summary

The document addresses why standard option pricing models do not include a separate input for a company’s estimated economic growth, including for options with long maturities. Its central explanation is that expectations about growth are already reflected in the current stock price, which is an input to the option model.

It frames this as a conceptual insight associated with Black–Scholes and Merton: projected growth need not be added as a separate parameter when pricing from the stock price and other model inputs. The discussion offers no derivation, quantitative example, or comparison of model assumptions. It is a brief conceptual answer, so it does not explore how changing growth expectations might affect the stock price or how model limitations and market estimates could matter in practice.

Key ideas

• Expected company growth is reflected in the stock price used by an option pricing model.
• The explanation says growth need not appear as a separate option model parameter.
• The answer presents a conceptual rationale without quantitative examples or model limitations.

Tags

# Why is there no parameter for the estimated economic growth of a company in the option price model


# Why is there no parameter for the estimated economic growth of a company in the option price model












Can someone explain me why the economic growth of a company is irrelevant in determining the option price. Especially for options with a long maturity e.g. 5 years it seems to me that for a high growth company this can make a lot of a difference ?

## Answer by MonteCarloSims (score 3)

https://quant.stackexchange.com/a/44926

Estimated economic growth is built into the stock price. Therefore it is, albeit hidden, inside any model that takes stock price into account.

One of the puzzles of pre Black-Scholes world was how to incorporate projected growth into an option price. One of Black and Scholes' (and Merton) main realizations was that they didn't need to parameterize growth (or any other thing discounted in a stock price.)

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.