The U.S. Dollar Index (DXY), explained
Last updated: 2026-07-18
The U.S. Dollar Index (DXY) measures the dollar against a basket of six major currencies — the euro (by far the largest weight), yen, pound, Canadian dollar, Swedish krona and Swiss franc. A rising DXY means a broadly stronger dollar. It is one of the biggest drivers of global capital flows: a strong dollar tends to pull capital into U.S. assets and pressure emerging markets. Descriptive, not investment advice.
What the DXY measures and which currencies it holds
The DXY, administered by ICE, tracks the dollar against six currencies with fixed weights — the euro dominates at roughly 58%, followed by the yen, pound, Canadian dollar, Swedish krona and Swiss franc. It launched in 1973 at a base of 100, so the level is relative to that starting point, not a price. Because the euro weight is so large, the DXY is really as much a euro story as a broad-dollar story.
DXY vs the Fed's trade-weighted dollar index
The DXY is the widely-quoted market index, but it only holds six developed-market currencies and no Chinese yuan. The Federal Reserve publishes its own trade-weighted dollar indexes (Broad, Advanced-Foreign-Economies and Emerging-Market), weighted by actual trade and covering many more currencies including the yuan. The Fed's Broad index is the better gauge of the dollar's overall external value; the DXY is the faster, more-traded market reference. They can diverge.
Why a strong dollar drives capital flows
A strong dollar is usually tied to higher U.S. rates or risk-off demand, and it has wide effects: capital rotates into dollar assets, emerging-market currencies and equities come under pressure as money leaves, dollar-priced commodities like oil and gold often fall, and U.S. multinationals' overseas earnings shrink when converted back. It is closely linked to how interest rates move capital — rate differentials are a main dollar driver.
What it means for Taiwan, the TWD and foreign flows
Taiwan is an export economy with heavy foreign participation in its stock market, so the dollar matters a lot. When the DXY rises, the TWD tends to weaken against the dollar and foreign investors often sell Taiwan equities and repatriate to dollar assets — a headwind for the TAIEX even if it can help exporters' reported earnings. A falling dollar tends to do the reverse. It is context for foreign flows, not a timing signal.
The dollar vs order flow and capital pressure
The dollar index is a slow, macro backdrop — the tide that lifts or lowers whole regions' capital. Order flow is fast and micro — who is the aggressor in a single market right now. See-Market's daily capital-pressure read sits on the equity indices in between. Read the dollar for the big-picture direction of global money, and the pressure board for the current lean. Watch it on the flow observatory. Not investment advice.
FAQ
What is the U.S. Dollar Index (DXY) in one sentence?
It is a market index (administered by ICE) measuring the dollar against a fixed basket of six major currencies — the euro, yen, pound, Canadian dollar, Swedish krona and Swiss franc — where a higher level means a broadly stronger dollar.
Which currencies are in the DXY, and what are the weights?
Six: the euro carries by far the largest weight (around 58%), followed by the Japanese yen, British pound, Canadian dollar, Swedish krona and Swiss franc. The weights are fixed, and there is no Chinese yuan — so the DXY leans heavily on the euro.
What does a rising dollar index mean for Taiwan stocks and the TWD?
Generally the TWD weakens against the dollar and foreign investors tend to sell Taiwan equities and move to dollar assets, which is a headwind for the TAIEX — though a weaker TWD can flatter exporters' reported earnings. It is context, not a signal, and other factors can dominate. Not investment advice.
How is the DXY different from the Fed's dollar index?
The DXY holds only six developed-market currencies (no yuan) with fixed weights. The Federal Reserve's trade-weighted indexes cover many more currencies, weighted by actual trade, and include the yuan — a broader gauge of the dollar's external value. The DXY is the more-traded market reference; the two can diverge.
Why does a strong dollar pressure emerging markets?
When the dollar strengthens, capital tends to flow out of emerging markets into dollar assets, EM currencies weaken (raising the cost of dollar-denominated debt), and dollar-priced commodities often fall. Together these tighten financial conditions for emerging economies. It is a broad tendency, not a rule for any single market.
Where can I see the dollar index?
The DXY is administered by ICE and quoted on most market-data sites in real time. For official trade-weighted measures, the Federal Reserve publishes daily Foreign Exchange Rates (release H.10), and the St. Louis Fed's FRED database carries the Nominal Broad U.S. Dollar Index with long history.
Not investment advice. The U.S. Dollar Index is a descriptive market measure of the dollar's strength against a basket of currencies — context for capital flows, not a buy/sell signal, and other factors can dominate any market. Sources: ICE (DXY administrator), U.S. Federal Reserve (Foreign Exchange Rates, H.10; trade-weighted dollar indexes), FRED (Nominal Broad Dollar Index).