The trades give Freddie a powerful incentive to do the opposite of its charter — to make home loans more accessible — highlighting a conflict of interest at the heart of the company.
Such an effort would "help the economy and put tens of billions of dollars back in consumers' pockets, the equivalent of a very long-term tax cut," says economist Christopher Mayer of the Columbia Business School. "It also is likely to reduce foreclosures and benefit the U.S. government" because Freddie and Fannie would have lower losses over the long run.
Freddie Mac's trades, while legal, occurred when the company was supposed to be reducing its investment portfolio, according to the terms of its government takeover agreement. But these trades escalate the risk of its portfolio, because the securities Freddie has purchased are volatile and hard to sell, mortgage-securities experts say.
The financial crisis in 2008 was made worse when Wall Street traders made bets against their customers and the public.
Now, some see similar behavior, only this time by traders at a government-owned company who are using leverage, which increases the potential profits but also the risk of big losses, and other Wall Street stratagems.
"More than three years into the government takeover, we have Freddie Mac pursuing highly levered, complicated transactions seemingly with the purpose of trading against homeowners," says Mayer. "These are the kinds of things that got us into trouble in the first place."
Here's how Freddie Mac's trades profit from homeowners unable to refinance. The mortgage sits in a big pile of other mortgages, most of which are also guaranteed by Freddie and have high interest rates. Those mortgages underpin securities divided into two basic categories.
One portion is backed mainly by principal, pays a low return and was sold to investors who wanted a safe place to park their money.
The other part, the inverse floater, is backed mainly by the interest payments on the mortgages. So this portion of the security can pay a much higher return, and this is what Freddie retained.
In 2010 and 2011, Freddie purchased $3.4 billion worth of inverse floater portions — their value based mostly on interest payments on $19.5 billion in mortgage-backed securities, according to prospectuses. They covered tens of thousands of homeowners. Most of the mortgages backing these transactions have high rates of about 6.5 to 7 percent, according to the deal documents.
In these transactions, Freddie has sold off most of the principal, but it hasn't reduced its risk.
First, if borrowers default, Freddie pays the entire value of the mortgages underpinning the securities, because it insures the loans.
It's also a big problem if homeowners refinance their mortgages. That's because a refi is a new loan; the borrower pays off the first loan early, stopping the interest payments. Since the security Freddie owns is backed mainly by those interest payments, Freddie loses.
And these inverse floaters burden Freddie with entirely new risks. With these deals, Freddie has taken mortgage-backed securities that are easy to sell and traded them for ones that are harder and possibly more expensive to offload, according to mortgage-market experts.
The inverse floaters carry another risk. Freddie gets paid the difference between the high mortgages rates and a key global interest rate that right now is very low. If that rate rises, Freddie's profits will fall.
It is unclear what kinds of hedging, if any, Freddie has done to offset its risks.
At the end of 2011, Freddie's portfolio of mortgages was just over $663 billion, down more than 6 percent from the previous year. But that $43 billion drop in the portfolio overstates the risk reduction, because the company retained risk through the inverse floaters.
The company is well below the cap of $729 billion required by its government takeover agreement.
Liz Day of ProPublica contributed to this story.