Skip to content

Comparing equally out-of-the-money calls and puts

Question

In a Black-Scholes world, compare a call struck 10%10\% above the current stock price with a put struck 10%10\% below it (same expiry). Which is worth more?

Short answer

The call. The lognormal distribution is right-skewed, so a 10%10\% rise is more likely than reaching 10%10\% down in the measure that matters, and a positive rate also raises the forward toward the call strike. For example, with S=100S = 100, σ=20%\sigma = 20\%, T=1T = 1, r=0r = 0 the call is about 4.294.29 and the put about 3.593.59.

Adapted from Crack, Heard on the Street, Q2.51, p.31; question and answer rewritten by SelfMadeQuant.com.

See the hint and the full worked solution in the question bank (free account).

Open the worked solution

Lessons behind this question

Start with a free lesson: Options is part of a free topic. Create a free account, no card needed, to read it in full with worked solutions.

Read it free