{"content_id":"arifdnfkbe","slug":"krw-jpy-decoupling-explained-and-fact-checked","locale":"en","schema_type":"Report","category":"report","category_name":"Report","title":"The Structure of Won–Yen Decoupling and How to Verify Exchange Rate Claims","summary":"Short-term decoupling between the won and yen can occur when interest rate expectations, capital flows, exporters’ currency conversions, and risk appetite affect the two countries differently. However, claims such as growth rates without a specified period or reference date and large-scale ADR financing must be independently verified using official exchange rate and disclosure data.","author":{"name":"Injoys Editorial Team","url":"https://injoys.com/ko/about"},"key_points":["Currency decoupling is a phenomenon in which two currencies that previously moved together move in different directions or with different degrees of strength over a certain period.","When the won strengthens while the yen weakens, the won exchange rate per 100 yen falls, but all three exchange rates must remain consistent under the cross-rate formula.","Net purchases of Korean stocks and dollar sales by exporters can strengthen the won, but the actual timing of currency conversion and whether currency hedging was used must be checked.","The US–Japan interest rate gap and the yen carry trade can explain yen weakness, but the trend can reverse quickly if policy expectations change.","Key figures presented, including SK hynix’s USD 25.6 billion ADR financing, are difficult to treat as confirmed facts without dates and official disclosures."],"content_markdown":"The Korean won and Japanese yen have often moved similarly because of shared factors such as dependence on crude oil imports, sensitivity to the global economy, and the influence of the U.S. dollar. However, this is not a fixed rule. If South Korea and Japan differ in their interest-rate outlooks, equity fund flows, and demand for foreign exchange related to trade payments, the won and yen may move in opposite directions.\n\nWhen evaluating exchange-rate claims, it is necessary to check not only the direction but also the **comparison period, reference point, exchange-rate quotation method, and official disclosures**. In particular, expressions such as “recently,” “the lowest in 40 years,” or “the highest appreciation rate among major currencies” are not enough to establish whether a claim is true unless a specific time frame is provided.\n\n## Conclusions to Check First\n\n- Short-term decoupling in which the won strengthens while the yen weakens is economically possible.\n- A statement that the won strengthened against the dollar generally means that the USD/KRW exchange rate fell.\n- A statement that the yen weakened against the dollar generally means that the USD/JPY exchange rate rose.\n- If these two movements occur at the same time, the won exchange rate per 100 yen falls.\n- However, the provided material does not include observation dates or official sources, and some corporate financing and investment amounts require separate verification through official disclosures.\n\nAccordingly, this issue should be read by separating “why decoupling is possible” from “whether the individual figures presented are factual.”\n\n## The Precise Meaning of Decoupling\n\nIn the foreign exchange market, decoupling refers to a phenomenon in which currencies or assets that normally show a high degree of synchronization move in different directions for a certain period or differ significantly in the scale of their fluctuations.\n\nThe won and yen do not always move in the same direction. Their synchronization may increase when the following factors affect them similarly.\n\n- Sensitivity to Asian manufacturing and global trade conditions\n- The impact of crude oil and raw-material import prices\n- U.S. interest rates and dollar strength\n- Risk aversion or risk appetite in international financial markets\n\nConversely, synchronization may weaken if South Korea and Japan differ in their policy-rate outlooks, expected growth rates, and securities fund flows. Moving in opposite directions for several days or weeks does not by itself confirm a long-term structural change.\n\n### Information Needed to Measure Decoupling\n\n1. Analysis start and end dates\n2. Whether the data use daily closing rates or intraday rates\n3. Whether the rates are against the dollar or effective exchange rates\n4. Return correlation coefficients over at least several months\n5. Whether movements before and after a specific event are statistically unusual\n\n“Twin currencies” is an informal market expression, not an economic law requiring the two currencies to move together.\n\n## The Relationship Among the Three Exchange Rates and How to Calculate Them\n\nTo interpret exchange rates, the direction of the quotation must first be checked.\n\n| Indicator | Meaning | General interpretation of a decline | General interpretation of an increase |\n|---|---|---|---|\n| USD/KRW exchange rate | Won required to buy 1 dollar | Won strengthens | Won weakens |\n| USD/JPY exchange rate | Yen required to buy 1 dollar | Yen strengthens | Yen weakens |\n| Won exchange rate per 100 yen | Won required to buy 100 yen | Won strengthens against the yen | Won weakens against the yen |\n\nThe three exchange rates are connected by the following cross-rate formula.\n\n**Won per 100 yen = 100 × USD/KRW exchange rate ÷ USD/JPY exchange rate**\n\nFor example, if the USD/KRW exchange rate is 1,450 won and the USD/JPY exchange rate is 160 yen, the theoretical won exchange rate per 100 yen is approximately 906 won.\n\n`100 × 1,450 ÷ 160 = 906.25`\n\nFor figures of 1,450 won per dollar and 800 won per 100 yen to be presented simultaneously, the USD/JPY exchange rate at the same point in time would have to be approximately 181.25 yen. It is therefore necessary to check whether exchange rates from different dates were mixed or how the “800-won range” was defined. Actual transaction rates may differ from theoretical values because trading spreads and fees are added.\n\n## Why the Won May Strengthen Relatively\n\n### Increase in Domestic Dollar Supply\n\nWhen exporters convert the dollars they receive into won, the supply of dollars in the foreign exchange market increases, putting downward pressure on the USD/KRW exchange rate. If companies expect the exchange rate to fall further and convert export proceeds earlier than usual, short-term movements may also be amplified.\n\nHowever, export proceeds are not necessarily converted in full immediately. Companies may retain the dollars for overseas investment, raw-material payments, or foreign-currency debt repayment, and they may also manage exchange-rate risk through forward exchange contracts and other instruments.\n\n### Foreign Purchases of Korean Stocks and Bonds\n\nWhen foreign investors sell dollars and buy won to purchase Korean assets, demand for the won may increase. An improving semiconductor industry, upward revisions to corporate earnings forecasts, and attractive valuations for Korean stocks may provide the backdrop for capital inflows.\n\nHowever, foreign investors’ net purchase amounts do not exactly equal spot foreign exchange purchases. This is because they may use won they already hold or use foreign exchange swaps and currency hedges. Trading statistics by investor type should be checked using Korea Exchange data with the period and market specified.\n\n### Changes in South Korea’s Growth and Interest-Rate Outlooks\n\nIf South Korea’s growth outlook improves or the Bank of Korea is expected to delay interest-rate cuts, the relative attractiveness of won-denominated assets may increase. Conversely, slowing exports, a surge in oil prices, geopolitical risks, and rising U.S. interest rates may weaken the won.\n\n## Why the Yen May Weaken Relatively\n\n### U.S.-Japan Interest-Rate Differential\n\nIf Japanese interest rates are lower than U.S. rates and the gap is expected to persist for a long time, investors have an incentive to borrow yen at low cost and invest in overseas assets expected to offer higher yields. If this process increases transactions involving the sale of yen and purchase of other currencies, it may put downward pressure on the yen.\n\nInterest-rate levels and differentials change from one meeting to another. Statements such as “Japan’s interest rate is 1%” or “it is 2.5 percentage points lower than the U.S. rate” must therefore include a reference date.\n\n### Yen Carry Trade\n\nThe yen carry trade is a strategy of borrowing yen at a low interest rate and investing in assets judged to offer relatively higher interest rates or returns.\n\nReturns are not guaranteed simply by the interest-rate differential. If the yen strengthens, the cost of repaying borrowed yen increases, potentially causing foreign exchange losses larger than the interest-rate differential. Tightening signals from the Bank of Japan, U.S. interest-rate cuts, and sharp increases in market volatility may trigger the unwinding of carry trades and lead to a rapid rebound in the yen.\n\n### Japan’s Growth Outlook and Policy Signals\n\nIf the growth outlook is weak and expectations spread that the Bank of Japan will find it difficult to raise interest rates quickly, the yen’s relative attractiveness may decline. Conversely, if wage and price increases continue and the possibility of further rate hikes grows, the yen’s weakness may ease.\n\nThe direction of policy should not be determined based solely on one phrase from the government or a statement by a politician. It is appropriate to review the Bank of Japan’s policy statement, economic and price outlook, and the governor’s press conference together.\n\n## Verification of the Figures and Statements Provided\n\nThe central logic of the provided material can be explained economically, but the following claims are difficult to confirm as stated because they lack dates and original sources.\n\n| Claim presented | Data needed for verification | Interpretive caution |\n|---|---|---|\n| The won appreciated 5.84% over one month, ranking first among major currencies | Start and end dates, list of comparison currencies, closing-rate basis | Rankings vary depending on the comparison group and time frame |\n| The yen reached a 40-year low against the dollar | Intraday or closing USD/JPY exchange rate on the relevant date | A “record low for the yen” has the same meaning as a record high for USD/JPY, and the basis for the record must be specified |\n| The won per 100 yen was in the 800-won range | USD/KRW and USD/JPY exchange rates at the same point in time | It must be checked against the cross-rate formula |\n| SK하이닉스 raised $25.6 billion through ADRs | Financial Supervisory Service DART, U.S. SEC, and official company disclosures | ADR registration and raising new funds are not the same concept |\n| Foreign investors net sold 149 trillion won in the first half of the year | Korea Exchange investor trading results by market | KOSPI and KOSDAQ, stocks and bonds, and trading value and net selling amount must be distinguished |\n| South Korea’s growth rate is projected to substantially exceed 3% | Forecasting institution, release date, and forecast year | Forecasts differ by release date and institution |\n| 40 trillion yen in loans is needed because of Japan’s investment in the United States | Government agreement, financing contracts by project, and guarantee structure | An investment commitment does not immediately lead to yen sales of the same amount |\n\n### Why Caution Is Needed Regarding ADRs\n\nAn ADR is a depositary receipt created to allow shares of a foreign company to be traded in the U.S. market. Merely establishing an ADR program or depositing existing shares does not provide the company with new funds. It is necessary to distinguish whether new shares were issued and sold, whether existing shareholders sold their holdings, and what the total amount and use of proceeds were.\n\nEven if a company raises dollars, it cannot be assumed that the full amount will be converted into won. The funds may be used for overseas capital investment or foreign-currency payments, converted in several stages, or currency-hedged. Therefore, a claim that large-scale currency conversion was a key cause of won strength must be supported by corporate disclosures and actual foreign exchange flows.\n\nBecause the provided figure of “$25.6 billion” represents an extremely large corporate financing transaction, the issuance structure and amount should first be checked through DART, SEC EDGAR, and official company announcements. Without confirmed official disclosures, it is difficult to cite it as an established fact or as a cause of exchange-rate movements.\n\n## Key Indicators to Watch Going Forward\n\n| Indicator | Potential impact on the won | Potential impact on the yen |\n|---|---|---|\n| U.S. policy rate and Treasury yields | Increases may put downward pressure on the won | A widening U.S.-Japan interest-rate differential may weaken the yen |\n| Bank of Korea policy signals | Hawkish signals may strengthen the won | Direct impact is limited |\n| Bank of Japan policy signals | Direct impact is limited | Growing expectations of rate hikes may strengthen the yen |\n| Foreign net purchases and sales of Korean securities | Net inflows may strengthen the won | Limited |\n| Dollar sales by Korean exporters | May strengthen the won | Limited |\n| International oil prices | A deterioration in South Korea’s trade balance may weaken the won | Higher import costs for Japan may weaken the yen |\n| Market volatility and risk aversion | May weaken the won | Carry-trade unwinding may strengthen the yen |\n| Dollar index | Dollar strength may weaken the won | Dollar strength may weaken the yen |\n\nTo assess whether short-term decoupling will persist, it is better to examine the following data together rather than focusing on a single day’s exchange rate.\n\n1. Daily and monthly exchange rates from the Bank of Korea’s ECOS\n2. USD/KRW, USD/JPY, and won per 100 yen data from the same point in time\n3. Foreign net purchases of stocks from the Korea Exchange\n4. Official policy decisions by the South Korean and Japanese central banks\n5. Growth forecasts from institutions such as the IMF, compared by release date\n6. Corporate DART and SEC disclosures and actual plans for the use of funds\n\n## Points of Caution for Individuals and Companies\n\n### Travelers and Consumers\n\nWhen the won exchange rate per 100 yen falls, fewer won are needed to buy the same amount of yen. However, actual costs, including bank and card issuer exchange spreads, overseas payment fees, and local prices, differ from market benchmark exchange rates.\n\n### Exporters\n\nWon strength may reduce the won-denominated value of dollar revenue. For Korean exporters competing with Japanese companies, the simultaneous strengthening of the won and weakening of the yen may increase the burden on price competitiveness. However, the impact differs by company depending on production locations, settlement currencies, and the share of imported raw materials.\n\n### Investors\n\nIt is risky to assume that a trend will continue based only on the recent direction of exchange rates. Unexpected central bank decisions or the unwinding of carry trades may cause both the yen and won to reverse quickly. Currency exposure and hedging costs should be considered together with asset returns.\n\n## Overall Assessment\n\nDecoupling between the won and yen may occur when interest-rate expectations, growth outlooks, securities fund flows, and corporate currency-conversion demand move differently in the two countries. In particular, if demand to buy the won and yen carry trades intensify at the same time, the combination of a stronger won and weaker yen may emerge.\n\nHowever, official data and clear reference dates are needed to establish that a particular company’s extremely large ADR financing, foreign investors’ net trading amount, or growth and policy-rate forecasts caused the decoupling. When citing exchange-rate articles or analyses, it is prudent to first verify the mathematical consistency of the three cross rates and the relevant disclosure documents.","content_html":"\u003cp\u003eThe Korean won and Japanese yen have often moved similarly because of shared factors such as dependence on crude oil imports, sensitivity to the global economy, and the influence of the U.S. dollar. However, this is not a fixed rule. If South Korea and Japan differ in their interest-rate outlooks, equity fund flows, and demand for foreign exchange related to trade payments, the won and yen may move in opposite directions.\u003c/p\u003e\n\u003cp\u003eWhen evaluating exchange-rate claims, it is necessary to check not only the direction but also the \u003cstrong\u003ecomparison period, reference point, exchange-rate quotation method, and official disclosures\u003c/strong\u003e. In particular, expressions such as “recently,” “the lowest in 40 years,” or “the highest appreciation rate among major currencies” are not enough to establish whether a claim is true unless a specific time frame is provided.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#conclusions-to-check-first\" class=\"anchor\" id=\"conclusions-to-check-first\"\u003e\u003c/a\u003eConclusions to Check First\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eShort-term decoupling in which the won strengthens while the yen weakens is economically possible.\u003c/li\u003e\n\u003cli\u003eA statement that the won strengthened against the dollar generally means that the USD/KRW exchange rate fell.\u003c/li\u003e\n\u003cli\u003eA statement that the yen weakened against the dollar generally means that the USD/JPY exchange rate rose.\u003c/li\u003e\n\u003cli\u003eIf these two movements occur at the same time, the won exchange rate per 100 yen falls.\u003c/li\u003e\n\u003cli\u003eHowever, the provided material does not include observation dates or official sources, and some corporate financing and investment amounts require separate verification through official disclosures.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eAccordingly, this issue should be read by separating “why decoupling is possible” from “whether the individual figures presented are factual.”\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#the-precise-meaning-of-decoupling\" class=\"anchor\" id=\"the-precise-meaning-of-decoupling\"\u003e\u003c/a\u003eThe Precise Meaning of Decoupling\u003c/h2\u003e\n\u003cp\u003eIn the foreign exchange market, decoupling refers to a phenomenon in which currencies or assets that normally show a high degree of synchronization move in different directions for a certain period or differ significantly in the scale of their fluctuations.\u003c/p\u003e\n\u003cp\u003eThe won and yen do not always move in the same direction. Their synchronization may increase when the following factors affect them similarly.\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eSensitivity to Asian manufacturing and global trade conditions\u003c/li\u003e\n\u003cli\u003eThe impact of crude oil and raw-material import prices\u003c/li\u003e\n\u003cli\u003eU.S. interest rates and dollar strength\u003c/li\u003e\n\u003cli\u003eRisk aversion or risk appetite in international financial markets\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eConversely, synchronization may weaken if South Korea and Japan differ in their policy-rate outlooks, expected growth rates, and securities fund flows. Moving in opposite directions for several days or weeks does not by itself confirm a long-term structural change.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#information-needed-to-measure-decoupling\" class=\"anchor\" id=\"information-needed-to-measure-decoupling\"\u003e\u003c/a\u003eInformation Needed to Measure Decoupling\u003c/h3\u003e\n\u003col\u003e\n\u003cli\u003eAnalysis start and end dates\u003c/li\u003e\n\u003cli\u003eWhether the data use daily closing rates or intraday rates\u003c/li\u003e\n\u003cli\u003eWhether the rates are against the dollar or effective exchange rates\u003c/li\u003e\n\u003cli\u003eReturn correlation coefficients over at least several months\u003c/li\u003e\n\u003cli\u003eWhether movements before and after a specific event are statistically unusual\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003e“Twin currencies” is an informal market expression, not an economic law requiring the two currencies to move together.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#the-relationship-among-the-three-exchange-rates-and-how-to-calculate-them\" class=\"anchor\" id=\"the-relationship-among-the-three-exchange-rates-and-how-to-calculate-them\"\u003e\u003c/a\u003eThe Relationship Among the Three Exchange Rates and How to Calculate Them\u003c/h2\u003e\n\u003cp\u003eTo interpret exchange rates, the direction of the quotation must first be checked.\u003c/p\u003e\n\u003cdiv class=\"overflow-x-auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eIndicator\u003c/th\u003e\n\u003cth\u003eMeaning\u003c/th\u003e\n\u003cth\u003eGeneral interpretation of a decline\u003c/th\u003e\n\u003cth\u003eGeneral interpretation of an increase\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eUSD/KRW exchange rate\u003c/td\u003e\n\u003ctd data-label=\"Meaning\"\u003eWon required to buy 1 dollar\u003c/td\u003e\n\u003ctd data-label=\"General interpretation of a decline\"\u003eWon strengthens\u003c/td\u003e\n\u003ctd data-label=\"General interpretation of an increase\"\u003eWon weakens\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eUSD/JPY exchange rate\u003c/td\u003e\n\u003ctd data-label=\"Meaning\"\u003eYen required to buy 1 dollar\u003c/td\u003e\n\u003ctd data-label=\"General interpretation of a decline\"\u003eYen strengthens\u003c/td\u003e\n\u003ctd data-label=\"General interpretation of an increase\"\u003eYen weakens\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eWon exchange rate per 100 yen\u003c/td\u003e\n\u003ctd data-label=\"Meaning\"\u003eWon required to buy 100 yen\u003c/td\u003e\n\u003ctd data-label=\"General interpretation of a decline\"\u003eWon strengthens against the yen\u003c/td\u003e\n\u003ctd data-label=\"General interpretation of an increase\"\u003eWon weakens against the yen\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\u003c/div\u003e\n\u003cp\u003eThe three exchange rates are connected by the following cross-rate formula.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eWon per 100 yen = 100 × USD/KRW exchange rate ÷ USD/JPY exchange rate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFor example, if the USD/KRW exchange rate is 1,450 won and the USD/JPY exchange rate is 160 yen, the theoretical won exchange rate per 100 yen is approximately 906 won.\u003c/p\u003e\n\u003cp\u003e\u003ccode\u003e100 × 1,450 ÷ 160 = 906.25\u003c/code\u003e\u003c/p\u003e\n\u003cp\u003eFor figures of 1,450 won per dollar and 800 won per 100 yen to be presented simultaneously, the USD/JPY exchange rate at the same point in time would have to be approximately 181.25 yen. It is therefore necessary to check whether exchange rates from different dates were mixed or how the “800-won range” was defined. Actual transaction rates may differ from theoretical values because trading spreads and fees are added.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#why-the-won-may-strengthen-relatively\" class=\"anchor\" id=\"why-the-won-may-strengthen-relatively\"\u003e\u003c/a\u003eWhy the Won May Strengthen Relatively\u003c/h2\u003e\n\u003ch3\u003e\n\u003ca href=\"#increase-in-domestic-dollar-supply\" class=\"anchor\" id=\"increase-in-domestic-dollar-supply\"\u003e\u003c/a\u003eIncrease in Domestic Dollar Supply\u003c/h3\u003e\n\u003cp\u003eWhen exporters convert the dollars they receive into won, the supply of dollars in the foreign exchange market increases, putting downward pressure on the USD/KRW exchange rate. If companies expect the exchange rate to fall further and convert export proceeds earlier than usual, short-term movements may also be amplified.\u003c/p\u003e\n\u003cp\u003eHowever, export proceeds are not necessarily converted in full immediately. Companies may retain the dollars for overseas investment, raw-material payments, or foreign-currency debt repayment, and they may also manage exchange-rate risk through forward exchange contracts and other instruments.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#foreign-purchases-of-korean-stocks-and-bonds\" class=\"anchor\" id=\"foreign-purchases-of-korean-stocks-and-bonds\"\u003e\u003c/a\u003eForeign Purchases of Korean Stocks and Bonds\u003c/h3\u003e\n\u003cp\u003eWhen foreign investors sell dollars and buy won to purchase Korean assets, demand for the won may increase. An improving semiconductor industry, upward revisions to corporate earnings forecasts, and attractive valuations for Korean stocks may provide the backdrop for capital inflows.\u003c/p\u003e\n\u003cp\u003eHowever, foreign investors’ net purchase amounts do not exactly equal spot foreign exchange purchases. This is because they may use won they already hold or use foreign exchange swaps and currency hedges. Trading statistics by investor type should be checked using Korea Exchange data with the period and market specified.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#changes-in-south-koreas-growth-and-interest-rate-outlooks\" class=\"anchor\" id=\"changes-in-south-koreas-growth-and-interest-rate-outlooks\"\u003e\u003c/a\u003eChanges in South Korea’s Growth and Interest-Rate Outlooks\u003c/h3\u003e\n\u003cp\u003eIf South Korea’s growth outlook improves or the Bank of Korea is expected to delay interest-rate cuts, the relative attractiveness of won-denominated assets may increase. Conversely, slowing exports, a surge in oil prices, geopolitical risks, and rising U.S. interest rates may weaken the won.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#why-the-yen-may-weaken-relatively\" class=\"anchor\" id=\"why-the-yen-may-weaken-relatively\"\u003e\u003c/a\u003eWhy the Yen May Weaken Relatively\u003c/h2\u003e\n\u003ch3\u003e\n\u003ca href=\"#us-japan-interest-rate-differential\" class=\"anchor\" id=\"us-japan-interest-rate-differential\"\u003e\u003c/a\u003eU.S.-Japan Interest-Rate Differential\u003c/h3\u003e\n\u003cp\u003eIf Japanese interest rates are lower than U.S. rates and the gap is expected to persist for a long time, investors have an incentive to borrow yen at low cost and invest in overseas assets expected to offer higher yields. If this process increases transactions involving the sale of yen and purchase of other currencies, it may put downward pressure on the yen.\u003c/p\u003e\n\u003cp\u003eInterest-rate levels and differentials change from one meeting to another. Statements such as “Japan’s interest rate is 1%” or “it is 2.5 percentage points lower than the U.S. rate” must therefore include a reference date.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#yen-carry-trade\" class=\"anchor\" id=\"yen-carry-trade\"\u003e\u003c/a\u003eYen Carry Trade\u003c/h3\u003e\n\u003cp\u003eThe yen carry trade is a strategy of borrowing yen at a low interest rate and investing in assets judged to offer relatively higher interest rates or returns.\u003c/p\u003e\n\u003cp\u003eReturns are not guaranteed simply by the interest-rate differential. If the yen strengthens, the cost of repaying borrowed yen increases, potentially causing foreign exchange losses larger than the interest-rate differential. Tightening signals from the Bank of Japan, U.S. interest-rate cuts, and sharp increases in market volatility may trigger the unwinding of carry trades and lead to a rapid rebound in the yen.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#japans-growth-outlook-and-policy-signals\" class=\"anchor\" id=\"japans-growth-outlook-and-policy-signals\"\u003e\u003c/a\u003eJapan’s Growth Outlook and Policy Signals\u003c/h3\u003e\n\u003cp\u003eIf the growth outlook is weak and expectations spread that the Bank of Japan will find it difficult to raise interest rates quickly, the yen’s relative attractiveness may decline. Conversely, if wage and price increases continue and the possibility of further rate hikes grows, the yen’s weakness may ease.\u003c/p\u003e\n\u003cp\u003eThe direction of policy should not be determined based solely on one phrase from the government or a statement by a politician. It is appropriate to review the Bank of Japan’s policy statement, economic and price outlook, and the governor’s press conference together.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#verification-of-the-figures-and-statements-provided\" class=\"anchor\" id=\"verification-of-the-figures-and-statements-provided\"\u003e\u003c/a\u003eVerification of the Figures and Statements Provided\u003c/h2\u003e\n\u003cp\u003eThe central logic of the provided material can be explained economically, but the following claims are difficult to confirm as stated because they lack dates and original sources.\u003c/p\u003e\n\u003cdiv class=\"overflow-x-auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eClaim presented\u003c/th\u003e\n\u003cth\u003eData needed for verification\u003c/th\u003e\n\u003cth\u003eInterpretive caution\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Claim presented\"\u003eThe won appreciated 5.84% over one month, ranking first among major currencies\u003c/td\u003e\n\u003ctd data-label=\"Data needed for verification\"\u003eStart and end dates, list of comparison currencies, closing-rate basis\u003c/td\u003e\n\u003ctd data-label=\"Interpretive caution\"\u003eRankings vary depending on the comparison group and time frame\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Claim presented\"\u003eThe yen reached a 40-year low against the dollar\u003c/td\u003e\n\u003ctd data-label=\"Data needed for verification\"\u003eIntraday or closing USD/JPY exchange rate on the relevant date\u003c/td\u003e\n\u003ctd data-label=\"Interpretive caution\"\u003eA “record low for the yen” has the same meaning as a record high for USD/JPY, and the basis for the record must be specified\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Claim presented\"\u003eThe won per 100 yen was in the 800-won range\u003c/td\u003e\n\u003ctd data-label=\"Data needed for verification\"\u003eUSD/KRW and USD/JPY exchange rates at the same point in time\u003c/td\u003e\n\u003ctd data-label=\"Interpretive caution\"\u003eIt must be checked against the cross-rate formula\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Claim presented\"\u003eSK하이닉스 raised $25.6 billion through ADRs\u003c/td\u003e\n\u003ctd data-label=\"Data needed for verification\"\u003eFinancial Supervisory Service DART, U.S. SEC, and official company disclosures\u003c/td\u003e\n\u003ctd data-label=\"Interpretive caution\"\u003eADR registration and raising new funds are not the same concept\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Claim presented\"\u003eForeign investors net sold 149 trillion won in the first half of the year\u003c/td\u003e\n\u003ctd data-label=\"Data needed for verification\"\u003eKorea Exchange investor trading results by market\u003c/td\u003e\n\u003ctd data-label=\"Interpretive caution\"\u003eKOSPI and KOSDAQ, stocks and bonds, and trading value and net selling amount must be distinguished\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Claim presented\"\u003eSouth Korea’s growth rate is projected to substantially exceed 3%\u003c/td\u003e\n\u003ctd data-label=\"Data needed for verification\"\u003eForecasting institution, release date, and forecast year\u003c/td\u003e\n\u003ctd data-label=\"Interpretive caution\"\u003eForecasts differ by release date and institution\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Claim presented\"\u003e40 trillion yen in loans is needed because of Japan’s investment in the United States\u003c/td\u003e\n\u003ctd data-label=\"Data needed for verification\"\u003eGovernment agreement, financing contracts by project, and guarantee structure\u003c/td\u003e\n\u003ctd data-label=\"Interpretive caution\"\u003eAn investment commitment does not immediately lead to yen sales of the same amount\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\u003c/div\u003e\n\u003ch3\u003e\n\u003ca href=\"#why-caution-is-needed-regarding-adrs\" class=\"anchor\" id=\"why-caution-is-needed-regarding-adrs\"\u003e\u003c/a\u003eWhy Caution Is Needed Regarding ADRs\u003c/h3\u003e\n\u003cp\u003eAn ADR is a depositary receipt created to allow shares of a foreign company to be traded in the U.S. market. Merely establishing an ADR program or depositing existing shares does not provide the company with new funds. It is necessary to distinguish whether new shares were issued and sold, whether existing shareholders sold their holdings, and what the total amount and use of proceeds were.\u003c/p\u003e\n\u003cp\u003eEven if a company raises dollars, it cannot be assumed that the full amount will be converted into won. The funds may be used for overseas capital investment or foreign-currency payments, converted in several stages, or currency-hedged. Therefore, a claim that large-scale currency conversion was a key cause of won strength must be supported by corporate disclosures and actual foreign exchange flows.\u003c/p\u003e\n\u003cp\u003eBecause the provided figure of “$25.6 billion” represents an extremely large corporate financing transaction, the issuance structure and amount should first be checked through DART, SEC EDGAR, and official company announcements. Without confirmed official disclosures, it is difficult to cite it as an established fact or as a cause of exchange-rate movements.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#key-indicators-to-watch-going-forward\" class=\"anchor\" id=\"key-indicators-to-watch-going-forward\"\u003e\u003c/a\u003eKey Indicators to Watch Going Forward\u003c/h2\u003e\n\u003cdiv class=\"overflow-x-auto\"\u003e\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eIndicator\u003c/th\u003e\n\u003cth\u003ePotential impact on the won\u003c/th\u003e\n\u003cth\u003ePotential impact on the yen\u003c/th\u003e\n\u003c/tr\u003e\n\u003c/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eU.S. policy rate and Treasury yields\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the won\"\u003eIncreases may put downward pressure on the won\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the yen\"\u003eA widening U.S.-Japan interest-rate differential may weaken the yen\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eBank of Korea policy signals\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the won\"\u003eHawkish signals may strengthen the won\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the yen\"\u003eDirect impact is limited\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eBank of Japan policy signals\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the won\"\u003eDirect impact is limited\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the yen\"\u003eGrowing expectations of rate hikes may strengthen the yen\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eForeign net purchases and sales of Korean securities\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the won\"\u003eNet inflows may strengthen the won\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the yen\"\u003eLimited\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eDollar sales by Korean exporters\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the won\"\u003eMay strengthen the won\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the yen\"\u003eLimited\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eInternational oil prices\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the won\"\u003eA deterioration in South Korea’s trade balance may weaken the won\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the yen\"\u003eHigher import costs for Japan may weaken the yen\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eMarket volatility and risk aversion\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the won\"\u003eMay weaken the won\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the yen\"\u003eCarry-trade unwinding may strengthen the yen\u003c/td\u003e\n\u003c/tr\u003e\n\u003ctr\u003e\n\u003ctd data-label=\"Indicator\"\u003eDollar index\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the won\"\u003eDollar strength may weaken the won\u003c/td\u003e\n\u003ctd data-label=\"Potential impact on the yen\"\u003eDollar strength may weaken the yen\u003c/td\u003e\n\u003c/tr\u003e\n\u003c/tbody\u003e\n\u003c/table\u003e\u003c/div\u003e\n\u003cp\u003eTo assess whether short-term decoupling will persist, it is better to examine the following data together rather than focusing on a single day’s exchange rate.\u003c/p\u003e\n\u003col\u003e\n\u003cli\u003eDaily and monthly exchange rates from the Bank of Korea’s ECOS\u003c/li\u003e\n\u003cli\u003eUSD/KRW, USD/JPY, and won per 100 yen data from the same point in time\u003c/li\u003e\n\u003cli\u003eForeign net purchases of stocks from the Korea Exchange\u003c/li\u003e\n\u003cli\u003eOfficial policy decisions by the South Korean and Japanese central banks\u003c/li\u003e\n\u003cli\u003eGrowth forecasts from institutions such as the IMF, compared by release date\u003c/li\u003e\n\u003cli\u003eCorporate DART and SEC disclosures and actual plans for the use of funds\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2\u003e\n\u003ca href=\"#points-of-caution-for-individuals-and-companies\" class=\"anchor\" id=\"points-of-caution-for-individuals-and-companies\"\u003e\u003c/a\u003ePoints of Caution for Individuals and Companies\u003c/h2\u003e\n\u003ch3\u003e\n\u003ca href=\"#travelers-and-consumers\" class=\"anchor\" id=\"travelers-and-consumers\"\u003e\u003c/a\u003eTravelers and Consumers\u003c/h3\u003e\n\u003cp\u003eWhen the won exchange rate per 100 yen falls, fewer won are needed to buy the same amount of yen. However, actual costs, including bank and card issuer exchange spreads, overseas payment fees, and local prices, differ from market benchmark exchange rates.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#exporters\" class=\"anchor\" id=\"exporters\"\u003e\u003c/a\u003eExporters\u003c/h3\u003e\n\u003cp\u003eWon strength may reduce the won-denominated value of dollar revenue. For Korean exporters competing with Japanese companies, the simultaneous strengthening of the won and weakening of the yen may increase the burden on price competitiveness. However, the impact differs by company depending on production locations, settlement currencies, and the share of imported raw materials.\u003c/p\u003e\n\u003ch3\u003e\n\u003ca href=\"#investors\" class=\"anchor\" id=\"investors\"\u003e\u003c/a\u003eInvestors\u003c/h3\u003e\n\u003cp\u003eIt is risky to assume that a trend will continue based only on the recent direction of exchange rates. Unexpected central bank decisions or the unwinding of carry trades may cause both the yen and won to reverse quickly. Currency exposure and hedging costs should be considered together with asset returns.\u003c/p\u003e\n\u003ch2\u003e\n\u003ca href=\"#overall-assessment\" class=\"anchor\" id=\"overall-assessment\"\u003e\u003c/a\u003eOverall Assessment\u003c/h2\u003e\n\u003cp\u003eDecoupling between the won and yen may occur when interest-rate expectations, growth outlooks, securities fund flows, and corporate currency-conversion demand move differently in the two countries. In particular, if demand to buy the won and yen carry trades intensify at the same time, the combination of a stronger won and weaker yen may emerge.\u003c/p\u003e\n\u003cp\u003eHowever, official data and clear reference dates are needed to establish that a particular company’s extremely large ADR financing, foreign investors’ net trading amount, or growth and policy-rate forecasts caused the decoupling. When citing exchange-rate articles or analyses, it is prudent to first verify the mathematical consistency of the three cross rates and the relevant disclosure documents.\u003c/p\u003e\n","tags":["Korean won","Foreign exchange market","Exchange rate","Japanese yen","Yen carry trade"],"faqs":[{"question":"Why does the USD/KRW exchange rate fall when the won appreciates?","answer":"The USD/KRW exchange rate is the amount of won needed to buy 1 U.S. dollar. If this figure falls from 1,500 won to 1,450 won, the same dollar can be bought with fewer won, so this is generally interpreted as an appreciation of the won."},{"question":"How do you calculate the won exchange rate per 100 yen?","answer":"Divide the USD/KRW exchange rate by the USD/JPY exchange rate at the same point in time, then multiply by 100. If USD/KRW is 1,450 won and USD/JPY is 160 yen, 100 yen is worth approximately 906 won."},{"question":"Are the won and the yen really twin currencies?","answer":"“Twin currencies” is a market term describing the tendency of two currencies to respond similarly to the global economy, commodity prices, U.S. interest rates, and other factors. It is not an official classification or a fixed relationship, and the degree of co-movement may vary depending on the analysis period."},{"question":"Does the won necessarily strengthen when foreign investors buy Korean stocks?","answer":"If they purchase won to invest in Korean stocks, it can contribute to won strength, but this is not necessarily reflected in the exchange rate on the same scale. They may use existing won funds, foreign exchange swaps, currency hedging, and other methods, while other capital outflows may offset the effect."},{"question":"Does issuing ADRs mean converting all the dollars raised into won?","answer":"No. ADRs may be traded by depositing existing shares, or funds may be raised through new shares. Even if new dollars are raised, they may be used for overseas investments and foreign-currency payments or converted in installments, so it should not be assumed that the entire amount will be converted into won."},{"question":"Why is the yen carry trade a factor in yen weakness?","answer":"When investors sell yen borrowed at low interest rates and buy foreign-currency assets they believe offer higher interest rates or returns, demand to sell the yen may increase. Conversely, if risk rises and they unwind their trades, they must buy back the yen, which can cause it to appreciate rapidly."},{"question":"How can you verify the claim that the yen is at a 40-year low?","answer":"You must first check the comparison currency, the reference date, and whether the price is intraday or the closing price. A record low for the yen against the dollar usually means a record high in the USD/JPY exchange rate, and it should be compared with historical records on the same basis using official daily time-series data."},{"question":"If the won and the yen move in opposite directions for several days, is that structural decoupling?","answer":"It is difficult to say definitively. They may diverge in the short term because of temporary currency conversions by companies or specific policy remarks, so it is necessary to check correlations over several months or longer, interest-rate differentials, capital flows, and whether policy changes persist."}],"sources":[{"url":"https://ecos.bok.or.kr/","title":"Bank of Korea Economic Statistics System ECOS","type":"data_point"},{"url":"https://fred.stlouisfed.org/series/DEXKOUS","title":"FRED South Korean Won to U.S. Dollar Exchange Rate","type":"data_point"},{"url":"https://fred.stlouisfed.org/series/DEXJPUS","title":"FRED Japanese Yen to U.S. Dollar Exchange Rate","type":"data_point"},{"url":"https://www.boj.or.jp/en/mopo/index.htm","title":"Bank of Japan Monetary Policy","type":"source"},{"url":"https://data.krx.co.kr/","title":"Korea Exchange Information Data System","type":"data_point"},{"url":"https://dart.fss.or.kr/","title":"Financial Supervisory Service Electronic Disclosure System DART","type":"source"},{"url":"https://www.sec.gov/edgar/search/","title":"U.S. SEC EDGAR Search","type":"source"},{"url":"https://www.imf.org/external/datamapper/NGDP_RPCH@WEO/JPN","title":"IMF DataMapper Japan Real GDP Growth","type":"data_point"}],"images":[{"id":503,"url":"https://injoys.com/rails/active_storage/blobs/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NTk5NywicHVyIjoiYmxvYl9pZCJ9fQ==--388a7c89f718a5bc0991693606cebaa591c4d2d4/ai-e67565ec.webp","is_representative":true,"generation_method":"ai_image","license":"ai_generated","mime_type":"image/webp","translations":{"ko":{"alt":"상승하는 한국 태극 문양과 하락하는 일본 국기 문양, 환율 차트와 무역 흐름을 나타낸 일러스트","caption":"원화와 엔화의 엇갈린 흐름을 상승·하락 화살표와 경제 지표로 표현했다.","description":null},"en":{"alt":"Korean emblem rising and Japanese flag falling amid exchange-rate charts and trade flows","caption":"Diverging won and yen trends are illustrated with opposing arrows and economic indicators.","description":null},"ja":{"alt":"上昇する韓国の太極模様と下落する日本国旗の模様、為替チャートと貿易の流れ","caption":"ウォンと円の異なる動きを上下の矢印と経済指標で表している。","description":null},"es":{"alt":"Emblema coreano al alza y bandera japonesa a la baja entre gráficos cambiarios y flujos comerciales","caption":"Las tendencias divergentes del won y el yen se representan con flechas e indicadores económicos.","description":null},"id":{"alt":"Lambang Korea naik dan bendera Jepang turun di antara grafik kurs serta arus perdagangan","caption":"Perbedaan arah won dan yen digambarkan dengan panah berlawanan dan indikator ekonomi.","description":null},"pt":{"alt":"Símbolo coreano em alta e bandeira japonesa em queda entre gráficos cambiais e fluxos comerciais","caption":"As trajetórias divergentes do won e do iene são mostradas por setas e indicadores econômicos.","description":null},"zh-hant":{"alt":"韓國太極圖樣上升、日本國旗圖樣下滑，周圍有匯率圖表與貿易流向","caption":"韓元與日圓的分歧走勢以相反箭頭和經濟指標呈現。","description":null},"de":{"alt":"Steigendes koreanisches Symbol und fallende Japan-Flagge zwischen Wechselkursgrafiken und Handelsströmen","caption":"Die gegenläufigen Trends von Won und Yen werden mit Pfeilen und Wirtschaftsindikatoren dargestellt.","description":null}}},{"id":504,"url":"https://injoys.com/rails/active_storage/blobs/proxy/eyJfcmFpbHMiOnsiZGF0YSI6NjAwMywicHVyIjoiYmxvYl9pZCJ9fQ==--3469acf042863f444bcf6c1e24456dc51cc4dfbf/ai-53d74072.webp","is_representative":false,"generation_method":"ai_image","license":"ai_generated","mime_type":"image/webp","translations":{"ko":{"alt":"차트와 돋보기, 달력, 시계, 문서, 한일 간 무역·금융 흐름을 그린 인포그래픽","caption":"한국과 일본 사이의 경제 흐름을 분석하고 환율 주장을 검증하는 과정을 시각화했다.","description":null},"en":{"alt":"Infographic with charts, magnifier, calendar, clock, documents, and Korea–Japan trade and finance flows","caption":"The graphic visualizes analysis of economic flows between Korea and Japan for evaluating exchange-rate claims.","description":null},"ja":{"alt":"チャート、虫眼鏡、カレンダー、時計、書類、日韓の貿易・金融フローを描いた図解","caption":"韓国と日本の経済の流れを分析し、為替に関する主張を検証する過程を表している。","description":null},"es":{"alt":"Infografía con gráficos, lupa, calendario, reloj, documentos y flujos comerciales y financieros entre Corea y Japón","caption":"La ilustración representa el análisis de los flujos económicos entre Corea y Japón para verificar afirmaciones cambiarias.","description":null},"id":{"alt":"Infografik berisi grafik, kaca pembesar, kalender, jam, dokumen, serta arus dagang dan keuangan Korea–Jepang","caption":"Ilustrasi ini memvisualisasikan analisis arus ekonomi Korea dan Jepang untuk menguji klaim nilai tukar.","description":null},"pt":{"alt":"Infográfico com gráficos, lupa, calendário, relógio, documentos e fluxos comerciais e financeiros entre Coreia e Japão","caption":"A ilustração mostra a análise dos fluxos econômicos entre Coreia e Japão para verificar alegações cambiais.","description":null},"zh-hant":{"alt":"呈現圖表、放大鏡、日曆、時鐘、文件及韓日貿易與金融流向的資訊圖","caption":"此圖將韓國與日本之間的經濟流向分析及匯率論點驗證過程視覺化。","description":null},"de":{"alt":"Infografik mit Diagrammen, Lupe, Kalender, Uhr, Dokumenten sowie Handels- und Finanzströmen zwischen Korea und Japan","caption":"Die Grafik veranschaulicht die Analyse der Wirtschaftsströme zwischen Korea und Japan zur Prüfung von Wechselkursbehauptungen.","description":null}}}],"published_at":"2026-08-06T11:33:40+09:00","updated_at":"2026-08-06T11:33:40+09:00","license":"cc_by","translation_status":"reviewed","available_locales":["ko","en","ja","es"],"data_locales":["ko","en","ja","es","id","pt","zh-hant","de"],"url":"https://injoys.com/en/articles/krw-jpy-decoupling-explained-and-fact-checked"}