US Dollar Index Components & Currency Weights
The US Dollar Index (DXY) is often described as a measure of the dollar’s overall strength, but that description hides an important detail: DXY doesn’t measure the dollar against the whole world. It measures the dollar against a specific, fixed basket of just six foreign currencies, each assigned a different weight based on decades-old trade relationships. Understanding these components and their weightings is essential to interpreting what DXY is actually telling you — and where its blind spots lie.
The Six Currencies in the DXY Basket
DXY’s basket has remained essentially unchanged since 1999, when the euro was introduced and replaced several legacy European currencies that were part of the original 1973 index. Today, the basket consists of:
- Euro (EUR) – 57.6%
- Japanese yen (JPY) – 13.6%
- British pound (GBP) – 11.9%
- Canadian dollar (CAD) – 9.1%
- Swedish krona (SEK) – 4.2%
- Swiss franc (CHF) – 3.6%
These six weights sum to 100% and have not been rebalanced since the euro’s inclusion. That means the same currencies, in the same proportions, have driven the index for roughly a quarter-century, even as global trade patterns have shifted dramatically.
Breaking Down Each Component
Euro (EUR) – 57.6%
The euro is, by a wide margin, the most influential currency in the DXY calculation. It represents the currencies of the eurozone member countries, aggregated into a single currency since 1999. Because it carries well over half the total weight, movements in EUR/USD have an outsized effect on the index. When traders say DXY is “basically the inverse of the euro,” they’re referring to this dominant weighting. A significant rally or selloff in the euro will almost always move DXY in the opposite direction, regardless of what’s happening with the other five currencies.
Japanese Yen (JPY) – 13.6%
The yen is the second-largest component and reflects Japan’s status as one of America’s most significant trading partners and a major global reserve currency. The yen is also closely tied to global risk sentiment; during periods of market stress, the yen often strengthens as a safe-haven currency, which can partially offset dollar strength driven by other factors within the index.
British Pound (GBP) – 11.9%
The pound represents the United Kingdom, historically one of the US’s closest trade and financial partners. Movements in GBP/USD are influenced heavily by Bank of England policy decisions, UK economic data, and, in recent years, ongoing post-Brexit trade and economic dynamics. While its weight is meaningful, it’s dwarfed by the euro’s influence.
Canadian Dollar (CAD) – 9.1%
The Canadian dollar reflects the deeply integrated trade relationship between the US and Canada, one of the largest bilateral trading relationships in the world. The Canadian dollar is also considered a commodity currency, often moving in tandem with oil prices given Canada’s significant energy exports, which introduces a layer of correlation with global commodity markets into the DXY calculation.
Swedish Krona (SEK) – 4.2%
Sweden’s krona carries a relatively small weight in the index, reflecting a smaller, though still meaningful, trade relationship with the US. Movements in the krona tend to have limited standalone impact on DXY given its modest weighting.
Swiss Franc (CHF) – 3.6%
The Swiss franc holds the smallest weight in the basket, yet it carries outsized importance during periods of global uncertainty. Switzerland’s currency is widely regarded as one of the world’s premier safe-haven assets, alongside the dollar and yen, which means the franc can behave somewhat independently of typical trade-driven currency dynamics.
Why These Six Currencies — and No Others?
The composition of DXY reflects the trade relationships of the United States as they existed in 1973, with only one significant update: the introduction of the euro in 1999, which consolidated several European currencies (including the German mark, French franc, and others) into a single currency. Beyond that change, the basket has never been revised to reflect the modern global economy.
This is the single most important limitation to understand about DXY. Consider that the composition includes no currency from China, despite China being one of the United States’ largest trading partners for decades. It also excludes the Mexican peso, South Korean won, and Indian rupee — all currencies representing substantial and growing trade relationships with the US. The absence of these currencies means DXY captures dollar strength primarily against developed-market, historically significant partners rather than the full scope of America’s actual current trade flows.
How the Weights Affect the Index’s Behavior
Because the weights are fixed and heavily skewed toward the euro, DXY behaves somewhat differently than a truly representative trade-weighted index would. A few practical implications follow from this structure:
Euro-driven volatility dominates. Since the euro alone represents more than half the index, European Central Bank policy decisions, eurozone economic data, and political developments within the European Union often have a more immediate and pronounced effect on DXY than comparable developments in Canada, Sweden, or Switzerland.
Emerging market dynamics are invisible to DXY. Major currency moves in the Chinese yuan, Mexican peso, or Brazilian real have no direct mathematical effect on the index, even though these economies represent enormous and growing shares of US trade. Investors who want visibility into dollar performance against these currencies need to look elsewhere, such as at individual currency pairs or broader trade-weighted indexes.
Safe-haven flows can create unusual patterns. Because both the yen and the Swiss franc are considered safe-haven currencies, periods of global risk aversion can sometimes cause these currencies to strengthen against the dollar even while the dollar is strengthening against other components like the pound or krona. This can create more muted or complex DXY movements than a simple “flight to the dollar” narrative might suggest.
DXY vs. Broader Trade-Weighted Alternatives
Given these limitations, some investors and economists prefer to reference other dollar indexes alongside or instead of DXY. The Federal Reserve publishes its own Trade Weighted US Dollar Index, which includes a much broader and more current set of currencies — incorporating major partners like China, Mexico, and South Korea — and is periodically updated to reflect actual trade flows. This index tends to provide a more comprehensive picture of the dollar’s value across the full scope of US trade, though it is less commonly quoted in daily financial media compared to DXY.
DXY’s enduring popularity, despite its narrower and outdated composition, largely comes down to its long history, its tradability through futures and ETFs, and its simplicity as a quick daily reference point for currency market sentiment.
Final Thoughts
The US Dollar Index is built on a specific, fixed basket of six currencies — the euro, yen, pound, Canadian dollar, krona, and Swiss franc — with weights that haven’t meaningfully changed since the euro’s introduction in 1999. The euro’s dominant 57.6% weighting means DXY is, in practice, heavily influenced by eurozone developments, while significant US trading partners like China and Mexico have no representation in the index at all. Understanding this composition is essential for interpreting DXY correctly: it’s a useful, widely followed gauge of dollar strength against major developed-market currencies, but it is not a complete picture of the dollar’s standing across the full landscape of US global trade.
This article is for informational purposes only and does not constitute financial advice.