On the evening of Sunday 15 August 1971, US President Richard Nixon went on television to announce a package of extraordinary economic measures. The most consequential of them, the one that changed the international monetary system for good, was the suspension of the dollar's convertibility into gold. With that decision, remembered ever since as the Nixon Shock, the gold window closed: foreign governments could no longer exchange their dollars for US Treasury gold at the fixed price of 35 dollars an ounce. In practice it was the end of the Bretton Woods system that had governed international monetary relations since the end of the Second World War.
Why should this history interest a trader today? Because the forex market as we know it, with exchange rates floating freely every second on supply and demand, simply did not exist before that evening. For decades exchange rates had been set by governments. Within a couple of years of the Nixon Shock the major currencies began to float, and the largest financial market in the world was born. This guide covers how Bretton Woods worked, why it became unsustainable, what exactly happened in August 1971, and which consequences we are still living with.
Bretton Woods: the system born out of a war
To understand the Nixon Shock you have to start in July 1944, when delegates from 44 allied nations met at Bretton Woods, in New Hampshire, to design the monetary architecture of the post-war world. The aim was to avoid a repeat of the monetary chaos of the 1930s, with its competitive devaluations and protectionism, which had contributed to the Great Depression and to the war itself. That conference produced institutions still with us today, including the International Monetary Fund and what would become the World Bank, and above all it produced a system of fixed exchange rates centred on the US dollar. Our article on the history of forex and 1944 covers the conference itself in more detail.
The mechanism was elegant in structure. The dollar was pegged to gold at a fixed 35 dollars an ounce, a price set by law, and the United States undertook to convert foreign official dollar holdings into gold at that rate. Every other currency was in turn pegged to the dollar at fixed parities with minimal room to fluctuate. In effect the dollar was as good as gold, and all other money was defined in relation to the dollar. The system became fully operational in 1958, when the main European currencies returned to convertibility.
One clarification matters: gold convertibility applied to foreign official authorities, meaning governments and central banks, not to private citizens. Americans, for that matter, had faced heavy restrictions on holding monetary gold since the 1930s. Bretton Woods was therefore an indirect gold standard. The world trusted the dollar because the dollar was convertible into gold, but what circulated in daily life was dollars, not bullion.
The structural flaw: the Triffin dilemma
The system carried a congenital defect, one that began to show in the early 1960s and that economists know as the Triffin dilemma, after the economist who described it. The problem ran like this. For the world to grow and trade it needed international reserves, and those reserves were dollars. But the only way the United States could supply dollars to the rest of the world was to spend and import more than it earned, which meant running a persistent balance of payments deficit.
There is the contradiction: the better the system worked, the more dollars piled up abroad; and the more dollars piled up abroad, the wider the gap between dollars in circulation and the gold actually held as backing. By 1961 foreign dollar holdings had begun to exceed the US government's gold stock. The promise to convert all those dollars at 35 an ounce was becoming mathematically impossible to keep.
The numbers tell the trajectory. American gold reserves, which exceeded 20,000 tonnes after the Second World War, had fallen to under 9,000 tonnes by 1971, while foreign claims on those reserves kept growing. Meanwhile pressure on the free market price of gold forced the main central banks to coordinate: when the London price spiked towards 40 dollars an ounce in October 1960, eight central banks set up the London Gold Pool in November 1961 to sell gold and hold the price at 35. It was a plain symptom that the market no longer believed the official parity.
Making matters worse, through the 1960s the United States financed the Vietnam War and major domestic spending programmes at the same time, feeding inflation and deficits. International confidence in America's ability to honour gold conversion was evaporating, and some countries, with France at the front, began actively converting their dollars into gold and draining the reserves.
The Camp David weekend and the announcement
By the summer of 1971 the situation was untenable. Pressure on the dollar was mounting and the risk of a generalised run on conversion was real. From 13 to 15 August, Nixon withdrew to Camp David with around fifteen advisers, among them Federal Reserve Chairman Arthur Burns, Treasury Secretary John Connally, and Under Secretary for Monetary Affairs Paul Volcker, who years later would chair the Fed himself. That secret weekend produced the plan Nixon announced to the nation on the Sunday evening.
The package, presented as the New Economic Policy, contained three main measures. The first and most historic was the suspension of the dollar's convertibility into gold, the closing of the gold window. The second was a 90-day freeze on prices and wages to fight domestic inflation. The third was a 10 per cent surcharge on imports, designed as negotiating leverage to force other countries to revalue their currencies against the dollar.
A detail often forgotten: Nixon presented the suspension of convertibility as a temporary measure. It never was. The gold window, closed that evening, has never reopened. Domestically the announcement was a political success; abroad it landed with dismay, because it had been decided unilaterally, without consulting allies, and it overturned overnight the rules underpinning world trade. The following morning several European currency markets were effectively paralysed.
From the Smithsonian Agreement to floating: 1971 to 1973
The Nixon Shock did not move the world to floating rates overnight. There was first an attempt to save fixed exchange rates without the gold anchor. In December 1971, after months of negotiation, the G-10 countries signed the Smithsonian Agreement in Washington: the dollar was devalued against gold, the other major currencies were revalued against the dollar, and new fixed parities were set with wider fluctuation bands. The 10 per cent import surcharge was removed as part of the deal, about four months after it was imposed. Nixon called the accord the most significant monetary agreement in the history of the world.
History was less generous. The new Smithsonian parities did not survive market pressure. Speculation against the dollar continued, and in February 1973 a further devaluation was needed. Weeks later the dollar came under attack again, and this time nobody tried to prop the system up. In March 1973 the major currencies floated: exchange rates would from then on reflect market supply and demand rather than government decisions. Bretton Woods was finished, and a few years later international agreements formally acknowledged the new reality of floating rates.
As for gold, released from its administered price of 35 dollars an ounce, it began life as a market-priced asset. Anyone looking at gold quotations today, at vastly higher levels, is also looking at half a century of monetary history in which the metal is no longer the declared pivot of the system but remains a thermometer of confidence, or the lack of it, in paper money. Our piece on what actually drives the gold price looks at how that thermometer works in practice.
How modern forex was born
Here is the part that touches traders directly. Under Bretton Woods fixed rates, a currency market in the modern sense made little sense: rates were set by the authorities, swings were minimal, and speculating on currencies essentially meant betting on the rare and traumatic decisions of governments to devalue or revalue. With floating after 1973 everything changed. Currency prices became continuous variables, set every instant by trading.
From that moment the ecosystem we now take for granted was born and grew: the interbank currency market, currency futures launched in Chicago in 1972 in anticipation of the new floating world, hedging techniques for corporate exchange rate risk, macro analysis applied to currencies and, decades later, online retail forex. Every time a trader opens a EUR/USD chart and watches the price move, they are looking at a reality that exists only because the link between the dollar and gold was severed on 15 August 1971. For the longer arc of how that market developed afterwards, see our overview of the history and origins of forex trading.
Floating also brought volatility, which is risk and opportunity in the same package. The decades after 1973 produced currency moves unthinkable in the Bretton Woods era: the great dollar swings of the 1980s, the currency crises of the 1990s, coordinated central bank interventions, and extreme episodes such as the removal of the Swiss franc's cap in 2015. The flip side of freely floating currencies is that they can move a great deal, and sometimes violently. It is also why relationships between pairs matter so much now: our correlation page tracks how the majors move together or apart, something that had no meaning at all when every rate was pinned by decree.
The fiat world and its long-run consequences
The Nixon Shock opened the era we live in, the era of fiat currencies, money whose value is not guaranteed by a physical commodity but rests on confidence in the institutions issuing it, on central bank policy and on the strength of the underlying economies. Today's dollar is convertible into nothing. It has value because the world trusts, more or less, the American economic, legal and monetary system.
That transformation handed central banks enormous flexibility. Free of the gold constraint, the Federal Reserve and its peers can expand or contract money according to the needs of the cycle, as the responses to the great crises have shown. Supporters argue that flexibility has prevented depressions; critics argue it has enabled decades of debt expansion and periodic bursts of inflation that a gold anchor would have made impossible. Unsurprisingly, the debate over the merits of abandoning the gold standard has never really closed, and it resurfaces every time inflation bites or confidence in paper money wobbles.
Another long-run consequence is a paradox: the end of convertibility did not dethrone the dollar. On the contrary, the dollar remained the world's reserve currency without gold behind it, supported by the depth of American financial markets and the absence of a credible alternative, as our article on why the dollar dominates explains. The system born at Bretton Woods died between 1971 and 1973, but the centrality of the dollar, which was its heart, outlived the system itself.
What today's trader can take from it
The first lesson of the Nixon Shock is that the rules of the game on markets are not laws of nature. They are political constructions, and they can change, sometimes overnight. An exchange rate system that looked eternal was dismantled over a weekend at Camp David and announced in a television address. Anyone trading currencies should remember that behind the prices sit political and institutional decisions capable of redrawing the landscape without notice.
The second lesson concerns unsustainability that is visible in advance and ignored for years anyway. The Triffin dilemma had been known to economists since the early 1960s; American gold reserves had been falling in plain sight for years; the London Gold Pool was itself proof that the official price would not hold. Yet the system carried on until it could not. Markets often work this way: obvious imbalances can last far longer than expected, but when they resolve, they resolve quickly and painfully.
The third lesson is perspective. Every forex trader, every gold investor, every saver wondering whether their currency will hold its value is living inside the consequences of 15 August 1971. Understanding where the current system came from, and knowing that it is relatively young and has already changed radically once, brings a clearer head to today's debates about currencies, debt, inflation and the possible future of the international monetary order.
The evening money changed
15 August 1971 is one of those dates that separate a before and an after in economic history. Before: a world of fixed rates, the dollar pegged to gold at 35 an ounce and every other currency pegged to the dollar. After: floating currencies and fiat money, with exchange rates formed on markets and central banks managing money without a metallic anchor. In between sat a television address by a president under pressure, a secret weekend at Camp David, and an agreement that tried in vain to save what could be saved before the definitive float of 1973.
For anyone trading currencies this is not archaeology. It is the birth certificate of their market. Modern forex, with its vast liquidity and its volatility, exists because a system of fixed parities collapsed under the weight of its own contradictions. And the questions raised back then, about how far you can trust money anchored to nothing, how much debt a fiat system can carry, and what role gold plays as a refuge, are exactly the questions markets are still asking more than half a century after that Sunday evening in August.
