US Dollar Index (DXY)
The DXY was created in 1973, shortly after the Bretton Woods fixed-exchange-rate system collapsed and currencies began floating freely. It tracks the dollar against six currencies — the euro, Japanese yen, British pound, Canadian dollar, Swedish krona, and Swiss franc — weighted by trade importance. The euro alone makes up roughly 57.6% of the basket, which means the DXY is heavily influenced by the EUR/USD currency pair. You can follow the index in real time on the currencies page.
The index is quoted as a number anchored to a base value of 100 set in March 1973. A reading above 100 means the dollar buys more of that basket than it did at the baseline; a reading below 100 means it buys less. Suppose the index sits at 105 — that signals the dollar is roughly 5% stronger than its 1973 baseline against those six currencies. The percentage-change columns (day, week, month, year-to-date) are often more useful than the raw level for spotting momentum.
A common confusion is treating the DXY as a universal measure of dollar strength. Because the basket excludes major emerging-market currencies like the Chinese yuan, Mexican peso, or Indian rupee, the DXY can look strong even when the dollar is weakening against those currencies. The US Dollar Index guide covers alternative broader dollar measures that include a wider set of trading partners. Economists also watch the DXY alongside real exchange rates to separate nominal moves from inflation effects.