Stockholders in Fannie Mae and Freddie Mac took a beating last week when the federal government announced the takeover of the mortgage giants, but a number of Members of Congress may have actually benefited from the move because they were invested in the companies’ debt instead of their stock.

Analysts said Fannie and Freddie debt products did quite well in the buyout because the government has now essentially become the guarantor of that debt.

“In the rescue package that was put together … the bond holders are made whole. They get 100 cents on a dollar,” said Robert Wasilewski of Baltimore-Washington Financial Advisors.

Fannie and Freddie floated bonds to raise capital and packaged mortgages into collateralized mortgage obligations, which are essentially bonds backed by the value of the homes and guaranteed by the companies. In most cases, these bonds were viewed as being as good as government-backed bonds, analysts said, but there was never an explicit promise that the government would pay them off in the event of a crisis. While the Treasury Department has still not actually promised to back those bonds, “it is [now] closer to government-guaranteed than it ever was,” said Andrew McCormick, head of securitized products at T. Rowe Price. “People who owned that are really happy.”

Apparently, some of those happy people are Members of Congress.

According to financial disclosure forms filed this summer, more than a dozen Members held Fannie and Freddie debt products, in some cases thousands of dollars’ worth.

For example, Rep. Mary Bono Mack (R-Calif.) reported holding several Fannie Mae notes and bonds worth at least $110,000. Rep. Rodney Frelinghuysen (R-N.J) reported holding between $15,000 and $50,000 in a Fannie Mae bond and Rep. Carolyn Cheeks Kilpatrick (D-Mich.) reported the same value in a Freddie Mac bond. Sen. Thad Cochran (R-Miss.) reported five Freddie Mac CMOs with a total value of between $33,000 and $145,000.

McCormick said that while the value of a bond doesn’t increase, with the government takeover “the certainty is stronger” that the bond will be paid, “so the price that you could sell it for has gone up.” Several financial advisers said that since the Treasury Department’s announcement this weekend, some Fannie and Freddie bonds are now selling for more than their face value.

It is not clear, though, that all Members were winners.

Sen. Charles Schumer (D-N.Y.) reported two Fannie Mae holdings worth between $1,000 and $15,000 each. If these were stocks, not bonds, Schumer will likely see their value drop to next to nothing. A year ago, Fannie stock traded at $62 a share, and Freddie traded at just less than $60. This week, they were both trading at less than $1. The way Schumer reported his assets, it is impossible to tell whether he won or lost on the holdings.

Both Sen. Jeff Sessions (R-Ala) and Rep. Pete Sessions (R-Texas) reported thousands of dollars worth of Fannie and Freddie on their financial disclosure forms this summer, but neither indicated whether they were stocks or bonds.

Jeff Sessions’ $50,000-$100,000 investment in Freddie Mac was held jointly with his mother, though representatives of his office says they believe most of that asset had been sold earlier this year. Pete Sessions’ $50,000-$100,000 investment in Fannie Mae was in the name of one of his kids.

While many Members of Congress report owning Fannie and Freddie in some fashion, many others likely have small holdings in the two companies through mutual funds that are widely diversified. For instance, Rep. Carolyn McCarthy (D-N.Y.) filed with her financial disclosure form 100 pages of broker statements laying out details of her holdings, which include at least $32,000 worth of Fannie and Freddie bonds.

Jeff Broadhurst of Broadhurst Financial Advisors in Philadelphia said Members holding diversified investment funds are unlikely to see a major impact either way from the takeover of Fannie and Freddie, though “there will be some funds where the fund manager totally believed in Fannie and Freddie, and they will take a hit.”

Members report their assets once a year, and the reports they filed this summer reflect their holdings only as of December 2007. Many of these reports may be out of date, and a Member’s holdings may have changed before the takeover was announced.