The US dollar has moved in long cycles for the entirety of the post-Bretton Woods era. Each cycle has produced enormous consequences for the global economy — for emerging market debt burdens, for commodity prices, for cross-border investment flows, and for corporate earnings in every economy that trades with the US. Reading these cycles is one of the more useful analytical disciplines in international macro.
The cyclical pattern
Since 1971, the US dollar has moved through roughly three complete strengthening-and-weakening cycles, each lasting seven to ten years. The DXY index (dollar-weighted against a basket of major currencies) reached major peaks around 1985, 2001, and 2022. Between peaks were multi-year periods of decline that meaningfully reversed the prior strengthening.
The pattern is not perfectly cyclical, and the "cycle" framing may be partly retrospective — each period had its own specific causes. But the empirical pattern of multi-year sustained moves is real, and the consequences of each cycle for the global economy have been substantial.
The mechanism of dollar strength
A strong dollar typically arises from some combination of: US interest rates that are high relative to other major economies (attracting capital seeking yield); US economic growth that exceeds other major economies (attracting capital seeking growth); and global risk-off sentiment (increasing demand for the world's reserve currency).
The 2022 dollar surge was driven primarily by the first two factors. The Fed raised rates faster than the ECB or BoJ. US growth held up better than European growth (which was hit hard by the energy shock). The combination produced a nearly 20% DXY appreciation in less than a year — one of the sharpest moves in dollar history.
The consequences of dollar strength
A strong dollar has several channels through which it affects the global economy.
Emerging market debt burdens rise. Many EM sovereigns and corporates borrow in US dollars. When the dollar strengthens against their local currencies, the local-currency equivalent of their dollar debt rises. This can trigger debt crises in the most vulnerable economies — the 1997–1998 Asian financial crisis and the 1982 Latin American debt crisis both occurred during dollar-strength periods.
Commodity prices fall. Most global commodities are priced in dollars. When the dollar strengthens, the same commodity price in dollar terms represents less purchasing power in other currencies. Buyers in non-dollar economies face effectively higher commodity prices in their local currency, which reduces demand and pressures dollar-denominated prices downward.
US corporate foreign earnings translate lower. US multinationals with foreign revenue see their overseas earnings — when translated back to dollars — reduced by the currency effect. In the 2022 dollar surge, US multinationals like Coca-Cola, Procter & Gamble, and IBM reported meaningful foreign-currency headwinds to their earnings.
Non-US corporate earnings in dollar terms rise. The opposite effect. European and Asian companies whose earnings are in local currencies but whose stocks are held by dollar-based investors see their dollar-translated earnings rise when the dollar weakens. This is one reason non-US equity markets often outperform US markets in dollar-weakness periods.
The consequences of dollar weakness
Dollar weakness produces the mirror image. Emerging market debt burdens ease. Commodity prices rise in dollar terms. US multinationals get foreign-earnings tailwinds. Non-US equity markets face translation headwinds for dollar-based holders.
The 2003–2008 dollar-weakness period saw one of the largest emerging market equity outperformance episodes on record. MSCI Emerging Markets outperformed the S&P 500 by more than 100 percentage points cumulative over the period. Much of the outperformance reflected the currency translation effect — the underlying stock returns in local currency were more comparable to US returns than the dollar-translated numbers suggested.
The global liquidity connection
A subtler consequence of dollar cycles is their effect on global liquidity. Global banking systems fund large amounts of dollar-denominated assets through short-term dollar liabilities — an operation that requires continuous access to dollar funding through the FX swap markets. When the dollar strengthens sharply, dollar funding becomes more expensive and less available, tightening liquidity for institutions globally.
The BIS has documented this pattern extensively. Periods of rapid dollar appreciation correlate with declining cross-border bank lending, wider credit spreads in EM, and tighter global financial conditions independent of what any specific central bank is doing. This is one of the reasons dollar cycles have such large aggregate consequences — they operate through financial channels that are not fully captured in national economic statistics.
The current position
The dollar peaked in late 2022 and has since retraced meaningfully. DXY sits well below its 2022 high but remains above its 2010s average. Whether the current cycle is in a multi-year weakening phase, a consolidation before further strength, or a range-bound period is genuinely uncertain.
The factors that would support further weakness are Fed rate cuts that narrow the interest-rate advantage over other majors, continued fiscal expansion that raises long-run debt concerns, and any acceleration of non-US growth relative to US growth. The factors that would support further strength are persistent US economic outperformance, geopolitical events that trigger safe-haven flows, or any renewed inflation surge that reverses Fed cutting expectations.
The implications for portfolios
The dollar-cycle framework has several practical implications.
Currency-hedged versus unhedged foreign equity exposure produces materially different returns during strong dollar cycles. A US-based investor in unhedged international equities in the 2022 dollar surge saw much of the underlying local-currency return offset by the currency translation. A hedged investor captured the local-currency return without the offset.
Emerging market debt is highly sensitive to dollar cycles. EM sovereign debt in dollar-strength periods faces both duration risk and currency-driven credit deterioration risk. In dollar-weakness periods, both risks reverse. This is why EM debt is often described as a "dollar cycle" trade rather than a pure credit trade.
US corporate international exposure is a meaningful driver of aggregate US index earnings. Roughly 40% of S&P 500 revenue comes from outside the US. Dollar cycles therefore affect S&P 500 earnings materially — a tailwind in weak-dollar periods, a headwind in strong-dollar periods.
The rule to internalise
The US dollar's multi-year cycles are one of the most consequential drivers of returns in every non-US market and one of the more under-discussed drivers in US markets. Reading the cycle — understanding whether we are in a strengthening or weakening phase, and what the drivers of the current phase are — is a useful macro discipline for any investor with even modest international exposure. The specific direction of the next move is not knowable, but the framework for reading what is happening is available to any investor willing to spend the time building it.
Educational content only. Not investment advice.