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The US dollar as the world's reserve currency
Since 1944· Concept
Fact, law or dataA rule, statute, definition or measured number.
The dollar is the currency central banks hold most, and the one most used for trade, loans and currency trading.
See it on the Money & Finance map →How it works
About 58% of the world's disclosed foreign-exchange reserves were in dollars in 2024, against about 20% in euros (IMF). The dollar is on one side of about 89% of currency trades and invoices roughly half of world trade. Foreigners hold about $9 trillion of US Treasuries. The reasons: the deep, liquid Treasury market, open capital flows, strong courts, and network effects, since everyone uses dollars because everyone else does.
Why it matters
It lets the US borrow more cheaply and wield sanctions, the 'exorbitant privilege' French minister Valéry Giscard d'Estaing named in the 1960s, but keeps the dollar stronger, hurting US exporters.
Think of it like
Like an anchor tenant: shoppers come because everyone else does, and that self-feeding traffic is hard for a rival center to steal.
Facts, rules and data
IMF reserve (COFER) data, BIS currency-trading surveys, Treasury data on foreign holdings and the Fed's annual report on the international role of the dollar.
Debates and risks
The Triffin dilemma: supplying the world with dollars may require persistent US deficits that eventually undermine confidence. How long dominance lasts is debated.
Inside this (6)
Connections (13)
▸US Treasury securities are the core reserve asset behind The US dollar as the world's reserve currencyFact, law or data
The connection
Central banks need reserves that are safe, pay interest and can be sold in size any day. No other market offers all three at the scale of the nearly $30 trillion Treasury market, so holding dollar reserves largely means holding Treasuries. That steady foreign demand lowers US borrowing costs, by up to about 0.8 percentage point in one estimate.
When and why
Since Bretton Woods, especially since the 1970s. Foreigners hold about $9 trillion; Japan is the largest holder, followed by the UK and China (2025).
How we know
Treasury's monthly TIC data on foreign holdings, IMF reserve data, and Warnock and Warnock (2009), who estimated the yield effect of foreign buying.
Debates and risks
Foreigners' share of Treasuries fell from about half around 2008 to under a third; whether deficits or politics will erode appetite further is debated.
▸Bretton Woods agreement (1944) established The US dollar as the world's reserve currencyFact, law or data
The connection
The US held roughly two-thirds of the world's monetary gold in the late 1940s and was the largest economy left intact by the war. Bretton Woods put the dollar at the center: other currencies pegged to it, and only it was convertible to gold. Central banks therefore held dollars as reserves, displacing the British pound.
When and why
The July 1944 conference set the rules; by the 1950s the dollar had overtaken sterling as the main reserve currency.
How we know
IMF par-value records and reserve-composition data show the dollar replacing sterling after the war.
Debates and risks
Barry Eichengreen and Marc Flandreau found the dollar briefly passed sterling in the 1920s, so Bretton Woods may have formalized rather than created its lead.
▸The petrodollar: oil priced in dollars since the 1974 US–Saudi deal reinforced The US dollar as the world's reserve currencyMainstream view
The connection
Oil is the world's most-traded commodity. Pricing it in dollars means importers need dollars, and exporters with surpluses park them in dollar assets, mainly Treasuries and US bank deposits. This recycling created steady global demand for dollars and Treasuries just as the gold link ended, reinforcing the dollar's central role.
When and why
From the mid-1970s, led by Saudi Arabia and Gulf exporters, whose Treasury holdings grew through the 1970s and 1980s.
How solid is the link?
Treasury's TIC data on oil exporters' holdings; Saudi Arabia's holdings, kept secret until 2016, were then about $117 billion.
Debates and risks
Economists debate how much oil pricing still matters: some oil now trades in yuan, rubles or rupees, yet the dollar's reserve share has fallen only gradually.
▸De-dollarization and BRICS alternatives would erode The US dollar as the world's reserve currencyExperts disagree
The connection
Dollar dominance rests on network effects: everyone uses dollars because everyone else does. De-dollarization would chip at that through reserve diversification, local-currency trade and non-dollar payment systems. Network effects make dominance sticky, but a shift could speed up once enough users move. So far the erosion is gradual, mostly toward smaller currencies and gold rather than one rival.
When and why
Global and gradual since about 2000; the debate intensified after the 2022 sanctions on Russia and as BRICS expanded in 2024.
How solid is the link?
IMF COFER reserve data; the BIS survey shows the dollar on one side of about 89% of currency trades in both 2022 and 2025.
Debates and risks
A roughly 10% dollar slide in the first half of 2025, its worst start to a year since 1973, revived the debate; no rival yet offers comparable depth.
▸The euro and the European Central Bank is the main rival to The US dollar as the world's reserve currencyFact, law or data
The connection
The euro holds about 20% of global reserves, a distant second. It has a large economy and a credible central bank but no single safe bond: each member issues its own debt, so nothing matches the depth of the Treasury market. Joint EU borrowing for the post-COVID recovery fund, from 2021, was a step toward one.
When and why
Since 1999; the euro's reserve share peaked above 25% around 2009, before the debt crisis. ECB President Christine Lagarde called in 2025 for a 'global euro' moment.
How we know
IMF COFER data and the ECB's annual report, The international role of the euro.
Debates and risks
Whether the EU will issue enough common debt and unify its capital markets for the euro to truly rival the dollar.
▸The US dollar as the world's reserve currency makes it cheaper to fund The national debt and federal deficitsMainstream view
The connection
Central banks, foreign investors and global banks want dollar assets for reserves, trade and collateral, and Treasuries are the main one. That steady demand lets the US borrow at lower rates than its debt level alone might imply; researchers call the discount a 'convenience yield'. This is the mainstream view, though its size is debated.
When and why
Since the dollar's postwar rise at Bretton Woods (1944); foreigners hold about $9 trillion of Treasuries, roughly 30% of the public debt, down from about half around 2008.
How solid is the link?
Treasury's TIC data on foreign holdings; Krishnamurthy and Vissing-Jorgensen (2012) estimated Treasuries' safety-and-liquidity premium averaged about 0.7 percentage points from 1926 to 2008.
Debates and risks
Whether the privilege is eroding: in April 2025 Treasury yields rose while the dollar fell, unusual in a sell-off, and central banks have been buying gold.
▸Asian financial crisis and Korea's IMF bailout (1997) led Asia to stockpile reserves in The US dollar as the world's reserve currencyMainstream view
The connection
Burned by running out of dollars in 1997, Asian governments built huge reserves, mostly in US Treasuries, as self-insurance against another crisis. Korea's reserves grew from about $20 billion at the end of 1997 to over $400 billion; China's passed $3 trillion. That demand helped hold down US interest rates.
When and why
Across East Asia from 1998; world reserves rose from about $1.6 trillion in 1997 to about $12 trillion in the 2020s.
How solid is the link?
IMF reserve data, and Bernanke's 2005 'global saving glut' speech tying Asian reserve buildup to low US long-term rates.
Debates and risks
How much this saving glut lowered US rates and fed the 2000s housing bubble is debated, as is how long Asia keeps favoring dollars.
▸Zimbabwe hyperinflation (2008) ended when Zimbabweans adopted The US dollar as the world's reserve currencyFact, law or data
The connection
When no one would take Zimbabwe dollars, the government in early 2009 let people use US dollars, South African rand and other foreign money. Dollars quickly dominated, and inflation fell to single digits within months because the government could no longer print the money in use.
When and why
Zimbabwe, January–April 2009; the Zimbabwe dollar was suspended in April 2009 and formally demonetized in 2015.
How we know
Reserve Bank of Zimbabwe statements and IMF reports show prices stabilizing in 2009 after dollarization.
Debates and risks
Dollarization cost Zimbabwe its own monetary policy; its 2019 return to a local currency revived inflation, and rebuilding trust remains unresolved.
▸The digital dollar: stablecoins vs. a Fed-issued CBDC could extend or erode The US dollar as the world's reserve currencyExperts disagree
The connection
Supporters, including the US Treasury, say dollar stablecoins carry the dollar onto phones worldwide, where people prefer it to weak local money, and create demand for Treasuries. Critics, including the ECB and BIS, warn private tokens can suffer runs, weaken other countries' monetary control and invite backlash, while China's e-CNY builds a state-run alternative.
When and why
A live debate since Facebook's Libra plan in 2019, sharpened by the 2025 anti-CBDC order and GENIUS Act.
How solid is the link?
Arguments rest on stablecoin data and projections, not long history; the BIS 2025 annual report and Treasury statements set out each side.
Debates and risks
Whether stablecoins entrench the dollar, or eventually lead foreign governments to restrict dollar tokens to protect their own currencies.
▸Global money flows: how capital moves between countries run mostly through The US dollar as the world's reserve currencyFact, law or data
The connection
Most cross-border borrowing, trade invoicing and currency trading uses dollars even when no American is involved: a Korean shipbuilder selling to a Brazilian buyer typically bills in dollars. The dollar sits on one side of about 89% of currency trades, so flows between two other currencies usually pass through dollars.
When and why
Worldwide since the 1944 Bretton Woods system; measured in the BIS April 2025 survey and the Fed's annual report on the dollar's international role.
How we know
BIS currency-trading surveys, SWIFT payment data and research on dollar trade invoicing by Gita Gopinath and others.
Debates and risks
Whether sanctions, US deficits and new payment systems will gradually pull flows away from the dollar is debated; so far change is slow.
▸Eurodollars: the offshore dollar banking system extend the reach of The US dollar as the world's reserve currencyFact, law or data
The connection
Offshore banks lend dollars to companies and governments that never deal with a US bank, so dollar credit reaches far beyond US borders. That creates dollar debts worldwide, which in turn create worldwide demand for dollars to repay them, reinforcing the dollar's central role.
When and why
London from the late 1950s, later Tokyo, Singapore, Hong Kong and the Caribbean; about $13 trillion of offshore dollar credit today (BIS estimate).
How we know
BIS global liquidity indicators and the Fed's reports on the dollar's international role.
Debates and risks
Whether this web of offshore dollar debt strengthens the dollar's position or makes the whole system fragile is debated.
▸Central banks' FX reserves: about $13 trillion, ~57% in dollars are the yardstick for The US dollar as the world's reserve currencyFact, law or data
The connection
The IMF's COFER data report what share of central banks' reported reserves sits in each currency. The dollar's share, 56.7% in mid-2026 against about 71% in 2000, is the most-cited gauge of its reserve status. Part of each quarterly move is just exchange rates: a weaker dollar mechanically shrinks its share.
When and why
IMF, Washington; quarterly data since 1999 from about 149 reporting central banks.
How we know
COFER data and IMF analysis separating exchange-rate valuation effects from active buying and selling.
Debates and risks
The shift away from dollars has gone mostly to smaller currencies like the Canadian and Australian dollars, with only about a quarter to the yuan; why is debated.
▸BIS FX survey: about $9.6 trillion traded a day (April 2025) finds 89% of trades involve The US dollar as the world's reserve currencyFact, law or data
The connection
The dollar was on one side of 89% of currency trades in April 2025, about the same as in 2022, because most currencies trade through the dollar, even when swapping two other currencies, such as won for pesos. That 'vehicle currency' role is a pillar of reserve status.
When and why
BIS triennial survey, April 2025.
How we know
BIS survey tables by currency.
Debates and risks
Whether the yuan's rising share, 8.5% in 2025, will ever challenge the dollar's role.