Currencies without Cargo: When Capital Flows Replaced Trade

Amba Arjun

For generations, exchange rates were taught as the economy’s automatic stabiliser: countries that imported more than they exported would see their currency weaken until the balance returned.

This describes a beautifully self-correcting system.

And it increasingly describes a world that no longer exists.

The United States consistently imports more goods, services and capital than it exports. Even after narrowing in the third quarter of 2025, its deficit still remained significantly large at roughly $226 billion, and over 2024 it widened to about $1.13 trillion (close to 4% of GDP). (1)(2) Despite this, the dollar remains one of the world’s most widely held currencies, central to global trade, invoicing, reserves and financial markets. However, it has softened recently as investors anticipate lower interest rates and easing inflation pressures, and improving risk sentiment.(3) Yet this weakness has not amounted to a collapse. The dollar remains historically elevated and continues to attract safe-haven flows during periods of global uncertainty. This coexistence of persistent deficits and enduring strength presents a puzzle: exchange rates increasingly appear driven by capital flows and asset demands rather than trade balances.

The Classical Hypothesis: Before Capital Took Over

The textbook story offers a clear benchmark. Floating exchange rates are meant to police external imbalances: countries that persistently buy more from other economies than they sell should see their currencies depreciate, while surplus economies experience appreciation. The mechanism is intuitive. Paying for imports requires foreign currency, placing steady downward pressure on the domestic one. Depreciation then restores competitiveness as exports become cheaper, imports become more expensive and the trade gap narrows without government intervention. In this view, exchange rates act as the automatic stabiliser as they quietly guide economies back towards balance. The empirical prediction is therefore simple: over time, deficit countries should have weaker currencies than surplus countries. The question is not whether this logic is elegant, it is whether it still describes reality in a financially integrated world.

Reading the Evidence: When Currencies Stop Listening

Using data from The World Bank, Chart 1 captures the striking pattern of average current account positions across major economies.(4) Germany and Japan maintain stable surpluses throughout the period, while the United States and United Kingdom remain structurally in deficit. Australia and Canada oscillate but rarely reverse position for long. The key insight is persistence: external imbalances do not naturally converge towards zero, setting up the classical prediction that exchange rates should adjust to restore balance.

Chart 2 hence summarises these patterns over the 2010-2024 period. The imbalance is systematic rather than cyclical. If classical adjustment holds, these averages must map directly onto currency movements.

Yet, Chart 3 uses Effective Exchange Rate (EER) data from The BIS Data Portal to contradict this prediction.(5) The US dollar trended upwards despite persistent deficits while the Japanese Yen weakened even with surpluses. Other currencies moved largely sideways. Exchange rates fluctuate, but not in proportion to external balances, suggesting forces beyond trade, particularly financial conditions, dominate long run currency behaviour.

Chart 4 directly tests the classical prediction through a scatter plot. If trade balances drove exchange rates, deficit countries would cluster with depreciation and surplus countries with appreciation, forming an upward-sloping relationship. Instead, the relationship is weak and dispersed. The US Dollar appreciates despite deficits and the Japanese Yen depreciates despite surpluses while the others scatter around zero. The near-flat line suggests that external balances explain little of long-run currency behaviour in modern economies.

Why the Link Broke

The weakening relationship between trade balances and exchange rates reflects a deeper shift in what currencies now price. First, capital flows increasingly dominate trade flows. Global financial transactions dwarf the value of goods crossing borders, so exchange rates react more to portfolio allocation than import demand.(6) A country attracting investment inflows can sustain external deficits because it effectively exports financial assets instead of merchandise. The exchange rate therefore adjusts to capital movements rather than trade imbalances.

Second, the rise of safe-haven currencies alters adjustment dynamics. The US dollar, Swiss franc and Japanese yen often strengthen during risk-off periods regardless of their countries’ external positions.(7) Investors demand liquidity and security, not export competitiveness, causing currencies to gain even when trade fundamentals suggest depreciation.

Finally, asset attractiveness now matters more than goods trade. Deep financial markets, credible institutions and legal protections increase global demand for domestic securities. Exchange rates increasingly reflect the desirability of holding a nation’s assets rather than purchasing its exports. Together, these forces mean currencies no longer primarily equilibrate trade flows, they equilibrate global portfolios.

The Missing Mechanism: The NIIP Identity

The decisive break from the classical story appears on the international balance sheet. A country’s external position evolves according to:

NIIPt= NIIPt-1 + CAt + Valuation Effectst

The net international investment position (NIIP) measures a nation’s external wealth which is the difference between what it owns abroad and what foreigners own domestically. Traditional adjustment logic assumes the valuation term, which represents changes in a country’s external wealth due to movements in asset prices or exchange rates rather than trade, is small. Persistent current account (CA) deficits therefore accumulate foreign liabilities until the currency must depreciate to restore sustainability.

For the United States, however, valuation effects are large. Unlike most countries, the United States borrows in its own currency but invests abroad in foreign-currency assets. As documented by Gourinchas and Rey (2007), this asymmetry generates valuation gains when the dollar depreciates, stabilising the external balance sheet despite persistent deficits.(8)

In effect:

Valuation Effects ≈ -Current Account Deficit

The balance sheet stabilises without requiring exchange-rate depreciation. Adjustment occurs through capital gains rather than trade flows. The exchange rate therefore no longer acts primarily as a mechanism correcting goods imbalances, it reallocates wealth across international portfolios.

Steering Without the Old Compass

If exchange rates now respond primarily to capital flows rather than trade balances, policy priorities shift accordingly. Authorities can no longer rely on currency depreciation to correct external deficits; instead, markets react to interest-rate expectations, risk sentiment, and institutional credibility. Recent periods of pressure on the dollar, despite official commitments to a “strong dollar,” illustrate this tension: governments must balance domestic objectives such as growth and inflation against the need to maintain investor confidence.(9)

For reserve-currency issuers, credible macroeconomic policy and stable financial institutions remain essential to prevent destabilising capital flight. Exchange-rate stability depends less on trade competitiveness and more on the perceived safety of domestic assets. Meanwhile, surplus economies face the opposite challenge as persistent appreciation can suppress inflation and weaken export sectors, sometimes requiring monetary accommodation.

Finally, the trend toward de-dollarisation and reserve diversification, exemplified by calls for the renminbi’s internationalisation, highlights the need for coordinated frameworks to manage exchange-rate spillovers and global capital flows.(10)

Pricing Confidence, Not Cargo

The evidence suggests a clear shift in how currencies behave. In advanced, financially integrated economies, trade balances no longer provide a reliable guide to exchange-rate movements. The relationship between current-account positions and long-run currency performance is weak, while links to capital flows, risk sentiment and asset-market conditions are far stronger. Exchange rates now respond primarily to portfolio allocation and financial confidence rather than the balance of exports and imports.

Understanding currencies therefore requires a different lens: less attention to goods crossing borders and more to capital seeking safety and return. Today’s exchange rates are written in the language of capital, not cargo. The value of a currency is no longer a mirror of what a nation sells, but of how much the world trusts it as it is priced less in shipping containers and more in confidence.

References

“International Transactions | U.S. Bureau of Economic Analysis (BEA),” n.d. https://www.bea.gov/taxonomy/term/501.
TRADING ECONOMICS. “United States Current Account to GDP,” n.d. https://tradingeconomics.com/united-states/current-account-to-gdp.
“United States Dollar - Quote - Chart - Historical Data - News,” n.d. https://tradingeconomics.com/united-states/currency#:~:text=the%20previous%20session.-,Over%20the%20past%20month%2C%20the%20United%20States%20Dollar%20has%20weakened,macro%20models%20and%20analysts%20expectations.
World Bank Open Data. “World Bank Open Data,” n.d. https://data.worldbank.org/indicator/BN.CAB.XOKA.GD.ZS?name_desc=true&utm.
“Time Series Search | BIS Data Portal,” n.d. https://data.bis.org/search?q=eer.
Khalid, Imran, and Imran Khalid. “Finance, Not Trade, Runs the Global Economy.” CounterPunch.org, January 28, 2026. https://www.counterpunch.org/2026/01/28/finance-not-trade-runs-the-global-economy/.
“Client Challenge,” n.d. https://www.ft.com/content/4eb0c9cc-3d81-4860-b59a-7696305ce48f.
Gourinchas, Pierre-Olivier, Hélène Rey, and National Bureau of Economic Research. “From World Banker to World Venture Capitalist: US External Adjustment and the Exorbitant Privilege.” NBER Working Paper Series, August 2005. https://www.nber.org/system/files/working_papers/w11563/w11563.pdf.
Staff, Reuters. “U.S. Dollar Rebounds as Bessent Reaffirms U.S. Strong Dollar Policy.” BNN Bloomberg, January 28, 2026. https://www.bnnbloomberg.ca/business/2026/01/28/us-dollar-rebounds-as-bessent-reaffirms-us-strong-dollar-policy/.
Team, Ebm Admin. “Xi'S Push for Renminbi as a Global Reserve Currency.” European Business Magazine, February 9, 2026. https://europeanbusinessmagazine.com/business/why-xi-wants-the-renminbi-to-become-a-global-reserve-currency/.

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