Santander Plays Key Role as US Buys Argentine Peso to Back Milei

When US Treasury Secretary Scott Bessent decided Thursday to buy Argentine pesos in the market to shore up the South American economy, he didn’t turn to a US bank. Instead it chose Spain’s Banco Santander SA.

The choice of Santander to become Treasury’s conduit to the peso came down to two crucial factors. One, the Spanish lender is part of a small group of so-called primary dealers in US Treasuries, which means it has a long-standing relationship with the Federal Reserve. The other is that it has large markets teams in both New York and Buenos Aires.

A spokesman ...