USD/MXN — the Mexican peso, Banxico and the carry trade

In January 2025, two weeks after Donald Trump was sworn in for a second term, a single-sentence statement from the White House threatening 25 percent tariffs on Mexican goods knocked the peso from 20.40 to 21.30 over two sessions. For anyone who had held a short position in USD/MXN since 2023 to harvest the textbook carry trade, this was a lesson no manual quite prepares you for: the Mexican peso is a currency where rich interest income walks hand in hand with political risk of wildly variable intensity.

Why is the peso the king of emerging-market FX?

USD/MXN is quoted in the “how many pesos per dollar” convention — a rate of 20.00 means one US dollar buys twenty Mexican pesos. According to the Triennial Central Bank Survey published by the Bank for International Settlements in 2022, the pair accounts for roughly 2.5 percent of global daily foreign-exchange turnover — the highest share among emerging-market currencies, larger than USD/BRL, USD/INR, USD/ZAR and USD/TRY combined. That depth keeps ECN spreads inside a 25–50 pip range, while genuine exotics like USD/COP routinely trade above 200 pips.

From a macro perspective, Mexico is the tenth-largest economy in the world by GDP (roughly 1.8 trillion dollars), with an open economy where exports make up close to 40 percent of output. What gives the peso its distinctive personality is the blend of commodity-currency traits (Pemex oil, silver, copper) and industrial-currency traits (automotive, electronics, white goods). That mix makes it unusually sensitive to the global business cycle, the price of oil and decisions taken in Washington — all at the same time.

Banco de México — the bank whose credibility holds the rate

Banxico (short for Banco de México) is one of the most respected central banks in Latin America. It gained operational independence in 1994, two years after the tequila crisis taught the Mexican political class how expensive it can be to bend monetary policy to the electoral cycle. The formal inflation target is 3 percent, with a tolerance of plus or minus 1 percentage point, and policy-rate decisions are taken eight times a year on Thursdays.

The 2021–2023 cycle illustrates the philosophy: Banxico began tightening in June 2021 — seven months ahead of the Fed — and lifted the policy rate from 4.00 to 11.25 percent. Cuts only began in March 2024, once CPI inflation published by INEGI had settled durably below 5 percent. This “higher for longer” posture is the main reason the peso preserves positive real rates of 3–4 percent — one of the highest in the G20. The persistent divergence between central banks explains why the Banxico–Fed gap supports the peso structurally.

Five factors that really move the rate

Unlike the majors, where a macroeconomic calendar will explain most of the daily action, USD/MXN responds to a hierarchy of drivers in which political variables can erase six months of accumulated carry inside a few hours.

The most instructive comparison is 2024 versus 2025. In 2024 the peso behaved like a textbook example: Banxico patiently brought the policy rate down from 11.25 to 9.75 percent, inflation tracked the projection, and the nearshoring story (Tesla in Monterrey, Foxconn in Veracruz, BMW in San Luis Potosí) pulled USD/MXN toward 16.40 in June. Between November 2024 and January 2025, the mere prospect of a second Trump term and the early run of tariff announcements wiped out eighteen months of appreciation. The rate rebounded to 20.80, even though the rate differential had barely changed.

The peso carry trade — the arithmetic and its trap

The classic peso carry trade involves taking a short position in USD/MXN (long the peso) and holding it for weeks or months to bank the positive swap generated by the rate gap. Suppose a short position with a notional of 100,000 dollars: at the current 425 basis-point differential it throws off a daily positive swap of around 4–7 dollars, which over a year is 1,500–2,500 dollars — roughly 1.5 to 2.5 percent of notional in pure interest. If the peso also appreciates, as it did between 2022 and mid-2024, capital gains pile on top, and a well-timed trade delivered total returns of 20–25 percent over eighteen months. It is the same mechanic explained step by step in our guide to the USD/JPY carry trade — except that in the peso the interest premium is higher and the risk more abrupt.

The trap is the asymmetric payoff profile: steady interest income punctuated by bursts of sharp capital loss. In March 2020, during the Covid panic, USD/MXN shot from 19.00 to 25.80 in three weeks — short positions absorbed a 36 percent adverse move while annual carry was running at just 5–6 percent. In November 2016, on the night Donald Trump was first elected, the peso lost 13 percent in a single session.

“Emerging-market pairs such as the Mexican peso offer tempting interest-rate differentials, but their sharp moves can wipe out months of carry profits in a matter of days.” — Kathy Lien, Day Trading and Swing Trading the Currency Market, Wiley, 2016.

Volatility, shocks and the oil correlation

The peso carries a long gallery of crises embedded in market memory: the tequila crisis of December 1994 (a drop of roughly 50 percent in a week), the 2016 election shock, the Covid spike to 25.80 in March 2020, and the tariff reset of January 2025. The takeaway is straightforward: USD/MXN is not a stable, moderately volatile pair. A daily ATR of 1,500–3,500 pips is the calm baseline, but in crisis episodes it can stretch to 6,000–10,000 pips. Experienced peso traders set stops at 2–3 percent of the rate (1,500–2,500 pips for medium-term positions) and never tighter. The South African rand (USD/ZAR) shares the same risk-off-prone character — a second classic carry currency worth watching alongside.

The peso’s link to oil is often reduced to the slogan “Mexico equals oil,” which today is misleading. Pemex still contributes about 14 percent of federal budget revenue, but since 2018 the government has prioritised energy sovereignty — the new Dos Bocas refinery (340,000 barrels per day) cut the need to export crude. The peso–Brent correlation has weakened from around −0.70 in 2014–2018 to between −0.40 and −0.50 today. Oil remains a sensible supplementary indicator but not the sole driver — it is worth setting against the behaviour of gold (XAU/USD), which tends to rise during the same risk-off episodes in which the peso falls.

USMCA and the 2026 review — the largest political risk

USMCA — the trade agreement between the United States, Mexico and Canada — replaced NAFTA on 1 July 2020. From the peso’s point of view it is an existential document: more than 80 percent of Mexican exports head to the US market, and annual bilateral trade exceeds 800 billion dollars. The unprecedented feature of the agreement is the sunset clause: every six years the parties must formally affirm that it should continue, and the first review is scheduled for 1 July 2026.

Three scenarios stand out. A clean confirmation and an extension for another sixteen years would be neutral for the peso, with a possible small appreciation. A short extension with renegotiation of selected clauses (most likely the automotive rules of origin and the Labor Value Content provision) would mean moderate pressure, with the rate probably between 20.00 and 21.50. A US threat to withdraw is the hardest scenario to price, in which the peso could weaken by fifteen to twenty-odd percent. For the mechanics of the carry trade and its glossary definition, see the carry trade entry on ForexMechanics.

What now — your first step with the peso

USD/MXN is an instrument for a position trader with at least 10,000 dollars of capital and a horizon of several weeks to several months. Three rules. First, no scalping and no day trading — a spread of 50–120 pips and an ATR of 1,500–3,500 pips eliminate strategies built on small moves. Second, follow three calendars in parallel: Banxico decisions (eight Thursdays a year), INEGI’s CPI releases and the announcements of the Office of the US Trade Representative on tariffs and USMCA. Third, never hold a short position in USD/MXN over a weekend in which significant political statements are expected — Monday open gaps can reach 200–400 pips.

The concrete first step: open a micro lot (1,000 USD notional) and hold it for a quarter, logging the daily positive swap, the daily price change and the monthly running result. After three months you will have real data on your own risk tolerance, the actual swap cost at your chosen broker and your ability to hold the position through volatile weekend opens. Only then should you consider scaling to a larger size — not before.