What Moves the US Dollar Index (DXY)?

DXY is the dollar gauge most traders quote. Understanding what is inside it explains why it moves the way it does, and why it can mislead you if you trade pairs it barely includes.

What people on X are asking

Many threads start from scratch: "First, what is DXY?" Others connect it to trading decisions, like an August 2026 post warning that most retail traders open GBP/USD or EUR/USD "without checking one thing first. The US Dollar Index." Crypto traders debate its link with bitcoin too; one May 2026 post noted that "Euro dominates at 57.6% of the basket" before claiming a strong negative correlation with bitcoin, a figure we could not verify and do not repeat.

The fact-checked answer

What it is. The US Dollar Index, published by ICE, measures the dollar against a basket of six currencies: the euro, Japanese yen, British pound, Canadian dollar, Swedish krona and Swiss franc. Its base value of 100 dates to March 1973. The weights are fixed and the euro is by far the largest at about 57.6%, followed by the yen at about 13.6% and the pound at about 11.9%.

What that means. Because the euro is more than half of DXY, DXY and EUR/USD tend to move as mirror images. DXY says little about the dollar against China's yuan or Mexico's peso. The Federal Reserve's nominal broad dollar index covers many more trading partners, weighted by trade, and is a better measure of the dollar's overall value. Our EUR/USD and dollar index chart shows both.

Main drivers.

• Interest-rate differences. When US rates rise relative to rates in the euro area or Japan, holding dollars pays more, which tends to lift the dollar. Central-bank decisions and expectations for them are the biggest single driver. The Fed raised its target range to 3.75%–4.00% in September 2026 and held it there in October; see our rates chart.
• Relative growth. Stronger US growth attracts investment into US assets.
• Risk appetite. In global financial stress, investors have often rushed into dollars and US Treasuries.
• Trade and energy prices. Changes in trade balances and oil prices shift demand for currencies of importers and exporters.

Inverse links. Gold and many commodities are priced in dollars, so a stronger dollar often coincides with weaker gold, though not always.

Decision helper

Checklist

1. Know which side of the pair the dollar is on before reading DXY.
2. Check upcoming Fed, ECB and Bank of Japan decisions.
3. Compare DXY with the broad dollar index when making big-picture calls.
4. Do not treat a correlation as a fixed rule; they shift over time.

Common mistakes

• Treating DXY as "the dollar against the world".
• Doubling exposure by trading EUR/USD and DXY products in the same direction.
• Assuming a strong dollar always means falling stocks or crypto.

FAQ

What currencies are in DXY?

The euro, yen, British pound, Canadian dollar, Swedish krona and Swiss franc.

Why does the euro weigh so much?

The weights were set when the index was created and carried over to the euro when it replaced several European currencies.

Is DXY the same as the Fed's dollar index?

No. The Fed's broad index includes many more currencies and uses trade weights.

What makes the dollar strong?

Mostly higher relative interest rates, stronger relative growth and demand for safety in stressful markets.

Does a strong dollar hurt gold?

Often, because gold is priced in dollars, but real interest rates and investment demand also matter.

Can I trade DXY directly?

Through futures and some other products. These are leveraged and carry significant risk.