The Mathematics of Financial Markets: From Bachelier to Black-Scholes

Fabian Owuor
4 min readJun 25, 2024

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Photo by Antoine Dautry on Unsplash

In 1988, mathematician Jim Simons established the Medallion Fund, which would go on to deliver an astonishing 66% average annual return over the next 30 years, vastly outperforming the market. An initial investment of $100 in 1988 would have ballooned to over $8 billion by now, catapulting Simons to a net worth of $30 billion. Simons’ success contrasts sharply with the experience of Sir Isaac Newton, who lost a third of his wealth in a poor investment in 1720, lamenting that while he could calculate the motions of heavenly bodies, he could not fathom the madness of people. But what if we could calculate and anticipate this “madness”?

The Origins of Financial Mathematics
Louis Bachelier was a pioneer in applying mathematical principles to financial markets. A physics student, Bachelier found employment at the Paris Stock Exchange, where the chaotic environment of hand signals, shouting, and money-changing hands provided a live laboratory for his theories. Bachelier’s work laid the foundation for modern financial mathematics, transforming the way we understand and interact with financial markets.

The History and Mechanics of Options
Options, a type of financial derivative, have ancient origins. Around 600 BC, Thales of Miletus utilized an early form of options to capitalize on his prediction of a bumper olive harvest. Instead of purchasing costly olive presses, Thales secured the right to rent existing presses at a predetermined price, allowing him to profit when the demand for presses soared with the harvest.

A call option grants the holder the right, but not the obligation, to buy an asset at a specified strike price in the future. Conversely, a put option gives the right to sell an asset at a predetermined price. For instance, if Kenya Power and Lighting Company (KPLC) shares are trading at 200 KES, buying a call option at 20 KES grants the right to purchase shares at 200 KES in a year. If the stock price rises to 300 KES, the option holder can buy at 200 KES and sell at 300 KES, netting a profit of 80 KES per share after accounting for the option cost.

Predicting Stock Movements: Randomness and Efficiency
Stock prices are influenced by myriad factors, including weather, politics, culture, and technological innovation. This complexity makes precise predictions challenging. According to the Efficient Market Hypothesis (EMH), stock prices reflect all available information, and any attempt to predict future prices alters the present price, rendering accurate prediction impossible.

Despite this randomness, large collections of random variables often form a normal distribution, with most outcomes clustering around a central value. This concept helps in pricing options. The future price of a stock, spread over time, follows a normal distribution centered on the current price. This principle, linked to Joseph Fourier’s work on heat distribution, provides a mathematical framework for pricing options.

The Black-Scholes Model and Hedging Strategies
The Black-Scholes/Merton model revolutionized option pricing by combining randomness with market trends. This model calculates the fair price of options, facilitating a new way to hedge against risks. By dynamically adjusting their portfolios, traders can profit with minimal risk from fluctuating stock prices.

For example, if Bob sells Alice a call option and the stock price rises, Alice profits while Bob loses. However, Bob can hedge his risk by holding the underlying stock. If the stock price increases, Bob’s loss on the option is offset by the gain on the stock, and vice versa. This strategy, known as dynamic hedging, minimizes risk from price movements.

Photo by Shubham Dhage on Unsplash

Using Options to Lower Risks of Utility Tokens
In the burgeoning field of cryptocurrencies, particularly with utility tokens, the principles underlying options can play a crucial role in risk management. Utility tokens, which grant holders access to a company’s product or service, often experience high volatility similar to stocks.

By using options, investors in utility tokens can hedge against adverse price movements. For instance, purchasing put options on utility tokens allows investors to sell their tokens at a predetermined price, protecting against significant losses if the market value drops. Conversely, call options enable investors to lock in a purchase price, ensuring they benefit from price increases without the obligation to buy if the price remains unfavorable.

This strategic application of options can help stabilize investments in utility tokens, offering a financial buffer against the inherent volatility of the cryptocurrency market. Thus, just as options have transformed traditional financial markets, they hold the potential to mitigate risks and enhance returns in the dynamic world of digital assets.

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Fabian Owuor

I'm a Blockchain Developer and DeFi Expert, backed by extensive experience as a Laravel Developer and adept in Project Management.