In the past decade, some observers have noted an unusual aspect of the Mexican peso's behavior: During periods when the U.S. dollar has risen (fallen) against other major currencies such as the euro, the peso has risen (fallen) against the dollar. Very few other currencies display this behavior....

Facing a shortage of U.S. dollars and a growing need to support their dollar-denominated assets during the financial crisis, international firms increasingly turned to the foreign exchange swap market and other secured funding sources. An analysis of the ensuing strains in the swap market shows...