Milei spent months stockpiling dollars to steady Argentina's shaky finances, and it worked well enough that reserves climbed to a seven-year high. Then he eased his grip on the peso, and the currency had its worst stretch since the country's October elections.
Argentina lets the peso trade inside a currency band, which is just a floor and ceiling the government sets and defends.
Investors had grown more cautious in recent weeks, and when people get nervous about a currency, they tend to move their money into dollars instead.
That buying pushed the peso to about 1,442 per dollar and toward the weak end of its band, leaving it down roughly 21% over the past year.
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Letting a currency trade freely is like taking the training wheels off a bike, where the first wobble doesn't mean the rider can't make it work.
Milei is betting Argentina is finally steady enough to handle the swings, and the reserves back him up after reaching their highest level since 2019.
Reserves are simply the dollars a central bank keeps on hand, and they act as a cushion when a currency comes under pressure.
High inflation is still a problem at around 32% a year, though that is a steep drop from the nearly 300% pace the country saw back in 2024.
The peso has been shaky since a run on the currency began last fall, when locals rushed to swap pesos for dollars before they lost more value.
Milei's party did better than expected in October's midterm elections, which bought the government some room to ease its tight controls.
To make the shift smoother, the government has been slowly widening the peso's band in step with inflation, giving the currency a bit more room each month.
Argentina also leaned on a $20 billion loan from the International Monetary Fund last year, the global lender that steps in when countries hit financial trouble. Economy Minister Luis Caputo has ruled out a sudden devaluation, saying the current exchange-rate system will stay in place.
Whether this week's slide is a one-off wobble or the start of a longer drift toward the bottom of the band.
As one of the most closely watched emerging markets, Argentina's next move will ripple through stocks, bonds, and the price of everything locals buy.
Reserves are the cushion, and as long as they hold, Milei has room to let the peso find its own level. Eight weeks of calm just ended in one.
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