DXY Explained: How the US Dollar Index Moves and What It Signals
The Dollar Index (DXY) tracks the US dollar against six major currencies. Learn the basket weights, what moves it, how to read it, and how DXY signals filter through to stocks, bonds, gold and EM FX.
DXY measures the US dollar against six currencies. Euro alone is 57.6% of the basket, so EUR/USD largely IS DXY. Real moves come from Fed policy, US growth surprises and global risk flows. Read DXY with the 2-year yield and gold for the full dollar story.
What is DXY?
The US Dollar Index (DXY, ticker DX-Y.NYB on Yahoo and DXY on most platforms) is a geometric weighted average of the dollar against six major currencies. It launched in March 1973 at a base of 100 right after the Bretton Woods system collapsed and the dollar floated freely.
Crucially, the basket weights have NOT been updated since 1999 when the euro replaced ten European currencies. That makes DXY a slightly outdated mirror of US trade today (no yuan, no Mexican peso) but the ICE futures contract on DXY is still where global flow concentrates, which is why traders still anchor to it.
DXY basket weights (post-1999)
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%.
The euro's 57.6% weight is the single most important fact about DXY. EUR/USD inverted IS DXY for practical purposes; if EUR/USD drops 1%, DXY rises roughly 0.6% all else equal. The remaining 42% adds Japan, UK and Canada flavour, but euro dominance means EUR/USD desk flow drives the index.
What actually moves DXY
Three drivers in order of magnitude: (1) Fed policy expectations vs other G10 central banks, read off the 2-year yield spread; (2) US growth surprises, read off NFP, retail sales and ISM; (3) global risk flows, where flight-to-quality bids dollars and risk-on episodes sell them.
Specific event-day reactions: hawkish FOMC = DXY higher. ECB dovish surprise = DXY higher (via EUR/USD lower). BoJ hawkish surprise = DXY lower (via USD/JPY lower). Hot US CPI = DXY higher. Hot eurozone CPI = DXY lower. The mechanism is always relative rate expectations.
Levels traders watch: DXY 100 (psychological round), 102.50 (Q1 2024 pivot zone), 105 (multi-year resistance), 107 (cycle high test). On the downside, 99 (2024 low), 95 (multi-year support). Breaks of those levels typically trigger 1-2% follow-through across all dollar pairs.
How to read DXY against other assets
DXY vs gold: historically a strong negative correlation (rolling -0.6 to -0.8). When DXY rallies hard, gold typically retraces. The correlation breaks down during pure flight-to-safety episodes where both can rise together.
DXY vs S&P 500: weak and unstable correlation. The relationship strengthens negatively during EM stress episodes (strong dollar pressures multinationals' overseas earnings) and weakens in pure tech-led rallies.
DXY vs 10-year Treasury yield: positively correlated through most cycles. A rising yield reflects tighter Fed expectations, which lifts the dollar. The correlation broke briefly in late 2022 when yields rose on supply concerns rather than growth, but normally yields lead DXY by hours to days.
DXY vs EM FX: inverse and tight. When DXY breaks above resistance, USD/MXN, USD/ZAR, USD/INR all tend to climb in sympathy. EM central banks watch DXY explicitly when sizing their own interventions.
DXY in your portfolio context
Equity holders should read DXY trends because a sustained dollar uptrend compresses S&P 500 earnings (~40% of S&P revenues are international) and pressures emerging market exposure. A 10% DXY rally over 12 months has historically clipped 3-5 percentage points off S&P 500 EPS growth.
Commodity bulls should treat DXY as a major risk factor. Most commodities price in dollars, so a stronger dollar mechanically reduces non-US buyers' purchasing power and tends to drag commodity prices lower. The exception is when the dollar rallies because of acute risk-off — then gold can decouple to the upside.
Bond holders see DXY as a proxy for global capital flows into Treasuries. A weak dollar can coincide with foreign demand for US duration (yen-hedged Treasury buying flips on/off based on hedging cost), so a falling DXY plus rising long-end yields is unusual and worth investigating.
People also ask
What is the DXY?
DXY is the US Dollar Index, a basket measuring the dollar against six currencies: euro (57.6%), yen, pound, Canadian dollar, Swedish krona and Swiss franc. It's the most-traded proxy for overall dollar strength.
What is the formula for DXY?
DXY is a geometric weighted average. The simplified formula is 50.14348112 × USDEUR^0.576 × USDJPY^0.136 × USDGBP^0.119 × USDCAD^0.091 × USDSEK^0.042 × USDCHF^0.036. The constant 50.14 normalises to base 100 from March 1973.
Why is the euro so dominant in DXY?
The basket was set in 1973 around US trade partners then; when the euro replaced ten European currencies in 1999, the index simply summed their old weights into one euro entry. That made EUR's 57.6% weight the natural outcome of merging Germany, France, Italy, Netherlands and others.
What's the difference between DXY and the trade-weighted dollar?
DXY uses the 1973 basket without yuan or peso. The Fed's broad trade-weighted dollar index includes 26 currencies, with yuan as the largest weight (~16%), and updates weights annually. DXY is the tradable proxy; the Fed index is the accurate one for US trade.
What moves DXY?
Fed rate expectations vs other G10 central banks (read off the 2-year yield spread), US growth surprises (NFP, ISM, retail sales), and global risk flows. Hawkish Fed, strong US data, or risk-off episodes all lift DXY.
What is a high DXY level?
DXY traded between 90 and 115 across the 2020-2025 cycle. Above 105 is considered strong; above 110 is cycle-high territory historically associated with EM stress. Below 100 is dollar-weak. The 2022 peak around 114 was the highest in 20 years.
How do I trade DXY?
Direct exposure via ICE Futures DXY contract (symbol DX), the Invesco DB US Dollar Bullish ETF (UUP) or its bearish counterpart (UDN). Most retail traders trade DXY indirectly through EUR/USD, since the euro's 57.6% weight means the two move together.
Why does gold move opposite to DXY?
Gold is priced in dollars, so a stronger dollar mechanically makes gold more expensive in other currencies, dampening demand. Beyond that, both compete as macro hedges: when real US rates rise (lifting DXY), the opportunity cost of holding non-yielding gold rises too.
For today's DXY price, technical bias, central bank watch and catalysts, see the live desk brief.
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