Probability Density Function
A probability density function (PDF) is a mathematical function that describes the likelihood of a continuous random variable taking on a specific value. In the context of finance, the PDF of an asset's future price is central to modeling risk and pricing derivatives.
It provides the shape of the distribution, showing which outcomes are most probable and which are outliers. When we talk about fat tails in crypto, we are referring to a PDF that has more weight in the extremes than a standard normal distribution.
By integrating the PDF over a range of prices, we can calculate the probability of the asset finishing in the money. This is the foundation of option pricing, as the payoff is determined by the final price relative to the strike.
Understanding the PDF allows quants to build better models that account for the unique volatility and skewness of digital assets. It is a visual and mathematical representation of market uncertainty.
The PDF is the essential input for all probabilistic financial analysis.