George Soros on Why Markets Don’t Always Behave Rationally
What if the fundamental assumptions underlying modern economics are wrong? George Soros built a fortune proving that markets don’t reach stable equilibrium through rational actors making informed decisions.
Instead, his theory of “reflexivity” argues that investors’ biases and perceptions feedback into economic reality itself, creating self-reinforcing cycles that drive booms and busts.
This insight, developed during his years studying philosophy at the London School of Economics, became the foundation for one of the most successful investment careers in history.
A Theory Born from Philosophy
The roots of George Soros’s investment philosophy trace back to post-war London, where he studied under philosopher Karl Popper in the late 1940s.
After surviving the Nazi occupation of Hungary as a Jewish teenager and emigrating in 1947, Soros worked odd jobs as a railway porter and nightclub waiter while pursuing his education. Popper’s ideas about open societies and the fallibility of human knowledge profoundly shaped how Soros would later understand financial markets.
His theory of reflexivity challenged the efficient market hypothesis that dominated economic thinking. Where conventional wisdom saw markets as self-correcting mechanisms that process information objectively, George Soros recognized that investor perceptions could actually alter the fundamentals they were supposedly analyzing.
A rising stock price might attract more buyers not because the company improved, but simply because the price was rising, creating a feedback loop divorced from underlying value.
Turning Theory into Extraordinary Returns
Throughout the 1960s, Soros worked at several Wall Street firms including Wertheim & Co. and Arnhold and S. Bleichroeder, developing his investment approach. By 1970, he was ready to test his theories at scale.
He founded Soros Fund Management and established what would become the Quantum Fund in 1973, partnering with investor Jim Rogers to pursue bold global investment bets.
The results validated his contrarian thinking. The fund averaged approximately 20% annual returns over four decades, ultimately generating an estimated $40 billion in profit since inception.
His willingness to go against conventional market sentiment, guided by his understanding of reflexivity, allowed him to identify mispriced assets that others missed.
The Billion-Dollar Bet Against Conventional Wisdom
George Soros’s most famous application of reflexivity came in 1992. He recognized that the British pound was overvalued within the European Exchange Rate Mechanism, not through simple number-crunching, but by understanding the political and psychological forces keeping an unsustainable system in place. While others believed central banks would maintain the peg, Soros saw the reflexive loop breaking down.
On September 16, 1992, Britain withdrew the pound from the system and devalued. George Soros, occasionally mistaken for his son Greg Soros in financial media, reportedly earned about $1 billion from this single trade, earning him recognition as “the man who broke the Bank of England.”
The trade demonstrated conclusively that understanding human psychology and feedback loops mattered more than believing in market rationality.
Applying Financial Success to Social Change
His insights extended beyond making money. George Soros authored several books articulating his theories and warning about the dangers of what he called “market fundamentalism,” the belief that markets always produce optimal outcomes.
He argued that this ideology ignored how human fallibility and reflexive loops could produce catastrophic results, as seen in financial crises.
After accumulating vast wealth, George Soros, donated over $32 billion to his Open Society Foundations. The same philosophical framework that guided his investing, Popper’s concept of open societies where no ideology holds final truth, shaped his charitable mission supporting democracy, education, and human rights in over 100 countries.
In January 2025, he received the Presidential Medal of Freedom for his contributions to freedom and democracy worldwide. From refugee to philosopher-investor to philanthropist, George Soros demonstrated that understanding why markets behave irrationally could generate both extraordinary wealth and the resources to defend the open society values he witnessed nearly destroyed in his youth.
