More than half the 24 Mexicans included last July in Forbes' list of the world's super-rich are no longer billionaires because of the plunge in the peso, the magazine said.
"If Forbes were doing its world's billionaires ranking this January as opposed to last July, nearly 60% of the Mexican billionaires then identified would fail to qualify," the magazine in its latest issue.
Since the government devalued the currency Dec. 20 and later allowed it to float, the peso has fallen 35% against the dollar. Last week, the United States said it was working on an aid package to prop up the currency.
As a result of the decline, the net worth of 14 of Mexico's 24 tycoons fell below the $1-billion mark.
That 24 Mexicans made 1994's list of 358 billionaires--the figure is out of proportion to the country's place in the world's economy--should have been a signal that the peso was overvalued, Forbes said.
Carlos Slim Helu, chairman of Telefonos de Mexico, suffered the biggest decline as the drop in Telmex shares cut his wealth almost in half, to $4.4 billion from $8.5 billion.
Slim Helu is trying to make the best of the situation. He told Forbes that, among other things, he is lending money to Mexican banks and earning interest rates of as much as 60%.
"There's a lot of opportunity for investors who believe in the peso," Slim Helu said. "There are few businesses where returns equal 60%."
Other billionaires who saw their wealth diminished include the family of Emilio Azcarraga Milmo, chairman of Grupo Televisa, whose fortune fell to $2.9 billion from $7.3 billion. The Zambrano family, the owners of cement maker Cemex, saw their net worth fall to $1.8 billion from $3.8 billion.