US Dollar Index®, What It Is, and Its History

Six Currencies Used in the U.S. Dollar Index

Currency board
••• Photo: Ryan Peirce/Getty Images

The U.S. dollar index®  is a measurement of the dollar's value relative to a basket of six different foreign currencies, as measured by their exchange rates. Over half of the index's value is represented by the dollar's value measured against the euro. The other five currencies consist of the Japanese yen, the British pound, the Canadian dollar, the Swedish krona, and the Swiss franc. 

The Index Formula

The dollar index is calculated using the following formula of currency pairs:

USDX = 50.14348112 × EURUSD -0.576 × USDJPY 0.136 × GBPUSD -0.119 × USDCAD 0.091 × USDSEK 0.042 × USDCHF 0.036

The value of each currency is multiplied by its weight. Note that the weight is a positive number when the U.S. dollar is the base currency, and negative when the U.S. dollar is the quote currency. Euros and pounds are the only two where the U.S. dollar is the base currency. That's because they are quoted in terms of the dollar. For example, a euro is worth $1.13. The other four are quoted in terms of how many a U.S. dollar will buy. For example, a dollar is worth 109 yen. 

History

In 1973, the Federal Reserve created the index to keep track of the dollar's value. It was right after President Nixon abandoned the gold standard that year, which allowed the value of the dollar to float freely in the world's foreign exchange markets. Before the creation of the dollar index, the dollar was fixed at $35/ounce of gold and had been that way since the 1944 Bretton Woods Agreement.

The dollar index began at 100. The index has measured the percent change in the dollar's value since the establishment of its base value. It changes constantly in reaction to shifts in the ongoing forex trades.

For example, its all-time high was 163.83 on March 5, 1985. That meant the dollar was 63.83 percent higher than in 1973.

Its all-time low was 71.58 on April 22, 2008. That meant it was 28.42 percent lower than its inception. 

In 1985, the ICE Futures U.S. took over the management of the USDX. That's the year that futures trading on the USDX began. 

Historical Data

Here is U.S. dollar index® historical data, as measured by the DXY, for the last 10 years.

2007: The dollar's value, as measured by the DXY spot price,  was 76.70 on December 31.

2008: The dollar ended the year at 82.15 after falling to a low of 71.30 on March 17, 2008. That was shortly after the Bear Stearns bailout signaled damage from the subprime mortgage crisis. At that time, investors thought it only affected the United States, and bought euros. The Fed lowered the fed funds rate 8 times. It initiated quantitative easing on November 25. By the end of the year, it was clear the 2008 financial crisis was worldwide. Investors returned to the dollar as a safe haven.

2009: The DXY ended the year at 77.92. The European Central Bank lowered rates, signaling it was responding to the crisis. The dollar fell as investors confidence in the euro rose. 

2010: The DXY rose to 88.26 on June 4, marking its high for the year. It fell to 78.96 by the year's end despite the Fed's launch of QE 2 on November 3.

2011: On May 2, the DXY fell to 73.10 due to the U.S. debt crisis. Investors returned to the dollar after the eurozone crisis. The Fed launched Operation Twist in September. The DXY ended the year at 80.21.

2012: The Fed announced QE3 on September 13 and QE4 in December. The DXY closed at 79.77.

2013: On June 19, the Fed announced it would taper off QE purchases. Investors sold bonds in a panic, driving the yield on the 10-year Treasury note up 1 percent. The Fed delayed tapering until December. The DXY closed the year at 80.04. 

2014: The dollar remained stable for the first six months, hitting 80.12 on July 10. The Ukraine crisis and Greek debt crisis drove investors out of the euro and into the dollar as a safe haven. The Fed ended QE in October. It held an unprecedented $4.5 trillion in Treasury notes.

 It announced it would raise the fed funds rate in 2015. By December 29, the dollar had risen 15 percent to 91.92.

2015: The European Central Bank announced it would begin QE in March. The euro fell to $1.0524 on March 12. The USDX hit the year's high of 100.18 on March 16, 2015. The dollar strengthened 25 percent from its 2014 low. On December 17, the Fed raised its benchmark rate to 0.5 percent. On December 27, the dollar ended the year at 98.69.

2016: On April 29, the dollar fell to its 2016 low of 93.08. On December 14, the Fed raised the fed funds rate to 0.75 percent. On December 11, it ended the year at 102.95. Since July 2014, it had risen 28 percent.

2017: Europe's economy improved, strengthening the euro. Hedge funds began shorting the dollar. The Fed raised rates on March 15, June 14, and December 13. On July 20, the European Central Bank signaled it might end QE in the fall. The dollar fell to 91.35, its low for that year, on September 8, 2017.  It ended the year at 92.12. 

2018: Early in the year, the dollar continued its decline. On February 15, the DXY fell to its low for the year of 88.59. That's down 14 percent from its 2016 high.  Investors were paring back their dollar investments as Europe's economy continued to strengthen. But then the U.S. economy improved while others' faltered. By August 14, the dollar index hit a one-year high of 96.73.

Historical Chart 

Year (last business day)DXY CloseFactors Driving Dollar's Value
1967 121.79Gold standard kept dollar at $35/oz.
1968 121.96
1969 121.74Dollar hit 123.82 on 9/30.
1970 120.64Recession.
1971 111.21Wage-price controls.
1972 110.14Stagflation.
1973 102.39Gold standard ended. Index created in March.
1974   97.29Watergate.
1975 103.51Recession ended.
1976 104.56Fed lowered rate.
1977   96.44 
1978   86.50Fed raised rate to 20 percent to stop inflation.
1979   85.82
1980   90.39Recession.
1981 104.69Reagan tax cut.
1982 117.91Recession ended.
1983 131.79Tax hike. Increased defense.
1984 151.47
1985 123.55Record of 163.83 on March 5.
1986 104.24Tax cut.
1987   85.66Black Monday.
1988   92.29Fed raised rates.
1989   93.93S&L Crisis.
1990   83.89Recession.
1991   84.69Recession.
1992   93.87NAFTA approved.
1993   97.63  Balanced Budget Act.
1994   88.69 
1995   84.83Fed raised rate.
1996   87.86Welfare reform.
1997   99.57LTCM crisis.
1998   93.95Glass-Steagall repealed.
1999 101.42Y2K scare.
2000 109.13Tech bubble burst.
2001 117.21Dollar rose to 118.54 on 12/24 after 9/11 attacks.
2002 102.26Euro launched as a hard currency at $.90.
2003    87.38Iraq WarJGTRRA.
2004   81.00 
2005   90.96War on Terror doubled debt. It weakened the dollar.
2006   83.43
2007   76.70Euro rose to $1.47.
2008   82.15Record low of 71.30 on 3/17.
2009   77.92ECB lowered rates. 
2010   78.96QE2.
2011   80.21Operation Twist. Debt crisis.
2012   79.77QE3 and QE4. Fiscal cliff.
2013   80.04Taper tantrum. Government shutdown. Debt crisis.
2014   90.28Ukraine crisis. Greek debt crisis.
2015    98.69Fed raised rates.
2016 102.21
2017   92.12EU strengthened.

(Sources: "DXY Interactive Chart," Marketwatch. A higher number indicates a stronger dollar. For data earlier than 2007: sourced  DX.F from Stooq.com.  It is a futures indicator that gives an idea of where the dollar stood compared to its history.

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