Pacific Investment Management Co.'s Bill Gross boosted the bond fund's mortgage-debt holdings to 59% of its assets in March, according to the firm's Web site. That's up from 23% in March of last year. Pimco's cash position dropped from 34% in February to 32% in March. Meanwhile, the fund has bet that Treasuries will fall. "Treasuries are the most overvalued asset in the world, bar none," Gross said on April 4.