How much is a Second Class stamp? mighty penegra after alcohol attended abide The giant fund-management firm, led by co-founder Bill Gross, started buying tens ofbillions of dollars in mortgage-backed securities guaranteed by federally sponsored agencieslike Fannie Mae and Freddie Mac. In the third quarter of 2011 alone, Pimco's flagship TotalReturn Fund, the world's largest mutual fund, doubled its holdings of these securities to $80billion, according to a Reuters review of trading and other data.