The Argentine peso has halted a five-day decline as the country prepares for a crucial vote this weekend, with the U.S. government seeking to assist its ally Javier Milei while Wall Street banks remain active in the local forex market.

According to informed sources, JPMorgan Chase and Citigroup were notably active in Argentina's spot currency market on Wednesday. The Argentine peso rose 0.1% against the dollar to 1,489 pesos, just two pesos shy of its lower trading range limit, after falling for five consecutive trading days.

Traders estimate that the scale of U.S. Treasury intervention is between $400 million and $500 million, marking the largest intervention to date. Official data has yet to be released. JPMorgan Chase and Citigroup declined to comment, and the U.S. Treasury has not responded to emailed requests for comment.

Argentina will hold a critical midterm congressional election this weekend, as Milei and U.S. Treasury Secretary Janet Yellen aim to prevent further depreciation of the peso. This election may determine the fate of the market-friendly reforms proposed by the liberal leader. On Tuesday, the peso approached its lower trading limit as voters rushed to hold hard currencies ahead of the polls. The currency's movements prompted the Argentine central bank to intervene for the first time in nearly a month, with assistance from the U.S. Treasury.

“The market will remain under pressure as the dollar supply from the business sector is limited, and sellers are waiting for the election results,” said economist Juan Manuel Truffa from local consultancy Outlier.