Probability Density Functions
A probability density function describes the likelihood of a continuous random variable, such as an asset price, falling within a particular range. In the context of binary options, traders use these functions to estimate the probability that the asset price will be above the strike price at expiration.
By integrating the probability density function from the strike price to infinity, one can determine the fair value of a digital call option. This mathematical approach is foundational to quantitative finance and helps traders price the all-or-nothing payoff accurately.
Different models assume different distributions, such as the log-normal distribution, which is common in Black-Scholes pricing. However, crypto markets often exhibit fat tails, meaning extreme price movements occur more frequently than standard models predict.
Adjusting the probability density function to account for these fat tails is a key skill for professional derivatives traders.