Because the US Dollar represents over 88% of all global currency transactions according to the Bank for International Settlements (BIS) Triennial Survey, analyzing individual currency pairs in isolation is rarely sufficient. Professional institutional traders consistently maintain an eye on the US Dollar Index (DXY)—the recognized international benchmark of overall greenback valuation.
1. What is the US Dollar Index (DXY)?
Created by the US Federal Reserve in 1973 following the dissolution of the Bretton Woods system, the DXY measures the general purchasing power of the US Dollar against a weighted basket of six major foreign currencies representing America’s primary historical trading partners.
2. The Currency Components and Weightings of DXY
| Currency | Country / Region | Basket Weight (%) |
|---|---|---|
| Euro (EUR) | Eurozone (20 Member Nations) | 57.6% |
| Japanese Yen (JPY) | Japan | 13.6% |
| British Pound (GBP) | United Kingdom | 11.9% |
| Canadian Dollar (CAD) | Canada | 9.1% |
| Swedish Krona (SEK) | Sweden | 4.2% |
| Swiss Franc (CHF) | Switzerland | 3.6% |
3. Why DXY is the Anti-EUR/USD Gauge
Notice that the Euro constitutes an overwhelming 57.6% of the entire DXY basket. Consequently, the price action of DXY and EUR/USD displays an almost perfect negative correlation of approximately -0.95:
- When DXY is rallying: EUR/USD is almost certainly declining.
- When DXY breaks key support: EUR/USD, GBP/USD, and Gold (XAU/USD) experience powerful upward breakouts.
Understand these multi-currency relationships in our guide on Understanding Currency Correlation in Forex and How to Trade Gold (XAU/USD).
4. Practical Trading Applications of DXY
- Confirming Breakouts: If EUR/USD breaks through resistance but DXY fails to break through its corresponding support level, beware of a false breakout (fakeout).
- Identifying Divergences: If DXY prints a higher high while USD/CHF fails to make a new high, underlying weakness exists in the USD/CHF pair.
Educational Disclaimer: This guide is intended purely for general informational and educational guidance. The DXY is an index and subject to market volatility. Consult our full Financial & Risk Disclaimer before trading.