Harry Geels: The role of coincidence in life and on the financial markets

December 2, 2025

During a holiday in a small coastal town in Northern Ireland, I once unexpectedly found myself sitting opposite my former geography teacher. A coincidence, you might think. But how coincidental is coincidence really? This question is more relevant than it seems: for investors, entrepreneurs and scientists, the way they deal with the unexpected often determines their success. In this column, I present a practical three-part framework that helps to better understand the role of coicidence. It builds on philosophical insights, but is primarily intended for application in the real world, from career opportunities to market dynamics.

1. Chance as a manifested small probability (outcome chance)

The first form of coicidence is the most intuitive: an unlikely event that actually occurs: winning the lottery, meeting the right person at the right time, or a roof tile falling on your head.

What characterises this form of coincidence:

• a chance was already known or implicitly present
• the outcome is extreme
• the event falls within a predictable range of possibilities

It is important to realise that coincidence only becomes meaningful when we observe it. Someone could lose the winning ticket. If I hadn't been sitting at that table in the Northern Irish restaurant, I might never have seen my old teacher. So coincidence requires not only probability, but also observation (and sometimes interpretation).

This type of coincidence is usually called chance. it refers to a small chance that manifests itself, either positively (luck) or negatively (bad luck).

2. Coincidence as contingency or “random walk” (process coincidence)

Whereas the first form relates to an outcome, the second form concerns the path along which events develop. This type of “coincidence” is omnipresent in the financial markets. Market prices move according to a dynamic of action and reaction: news, sentiment, trading systems, geopolitics and liquidity constantly influence each other. The result is a chaotic pattern with a certain bandwidth, but never a perfectly predictable course. Mathematically speaking, we also refer to this as a stochastic process.

This form of coincidence – referred to in English as “contingency” – describes the constant uncertainty in systems in which countless variables influence each other. It is reminiscent of the well-known “butterfly effect”: small events can have major consequences. The important thing here is that the uncertainty is structural. We know that the path is uncertain, but we do not know exactly how it will unfold. That is why a range of possible outcomes is often shown (using Monte Carlo analyses) instead of a single prediction.

This is essential for investors: those who build a portfolio as if the future were predictable will sooner or later face shocks. Those who accept that markets exhibit a random walk focus on robustness and diversification in their portfolios.

3. Coincidence as serendipity (meaningful coincidence)

The third form of coincidence is less statistical and more psychological: coincidence that not only occurs, but also acquires meaning. Serendipity is the unexpected insight or discovery that presents itself when you are receptive to it.

This is not mysticism, but an attitude: those who go through life with open attention see more possibilities and are quicker to make connections between seemingly unrelated events. As serendipity expert Pek van Andel put it: “serendipity is the art of loose blinders”. Or, as Paulo Coelho so beautifully wrote in his novel “Eleven Minutes” with regard to encounters with people: “Important encounters are planned by the souls long before the bodies see each other”.

Serendipity requires three things:

1. a “chance” event
2. the right mental state to recognise that event as valuable
3. the willingness to do something with it

This often plays a major role in innovation, entrepreneurship and career development. Many important discoveries, from penicillin to Post-it notes, were the result of a “chance” event, combined with attentive and creative thinking.

Coincidence and success according to Taleb

Probability professor and acclaimed philosopher Nassim Taleb argues that much of what we call “success” is actually luck. Not because people lack talent or commitment, but because outcome coincidence and process coincidence play a major role in the timing of opportunities.

However, Taleb is not fatalistic. He argues that we can increase our exposure to positive forms of “coincidence” and reduce our vulnerability to negative shocks. His concept of antifragility – building structures (or portfolios) that become stronger through volatility – fits perfectly with the recognition that the world is fundamentally uncertain.

Perseverance, discipline, passion and a growth mindset increase our chances of positive outcomes. Success has many fathers and mothers. The same applies in the financial world: a portfolio that can withstand unforeseen events is better prepared for the vagaries of the market.

Conclusion: understanding coincidence to act better

Coincidence is not one thing, but at least three things:

1. Outcome coincidence: a small probability that manifests itself (and is observed)
2. Process coincidence: the permanent uncertainty in the path of events
3. Meaning coincidence (serendipity): the unexpected find that you recognise and exploit

By distinguishing between these forms, we not only become better investors, but also better decision-makers in everyday life. Coincidence cannot be eliminated, but it can be understood. And those who understand it can use it to their advantage.

This article contains the personal opinion of Harry Geels

 

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