Dollar Index Limitations Revealed: Fed Favors Broader Trading Partner Weights

The widely used US Dollar Index (DXY) has several limitations when tracking the strength of the US dollar on the foreign exchange market. The DXY is heavily biased towards the Euro, which makes up 57.6% of the index, and also excludes some key trading partners of the United States, including China.

To address these issues, the Federal Reserve uses a different index called the Broad Dollar Index (DTWEXBGS). This index takes into account the trade flows with the US dollar's main trading partners and updates its weights regularly. For 2026, the Euro represents around 21% of the basket, while the Mexican peso accounts for 14.8%, the Canadian dollar 12.8%, and the Chinese yuan 10.9%. The Broad Dollar Index is an index weighted by trade in goods and services, making it a more accurate representation of the dollar's external value.

The use of both the DXY and the Broad Dollar Index can provide valuable insights into the strength of the US dollar. If the DXY falls but the Broad Dollar Index remains resilient, it may indicate that the weakness of the dollar is primarily related to the Euro. Conversely, if both indices decline simultaneously, it suggests a broad-based weakness in the dollar.