The Federal Reserve is trying to keep money cheap and announced that it would buy long-term Treasury securities. This is similar to the move it made in 2007 when it bought $1.25 trillion in mortgage-backed securities, and another $200 billion in debts owed by government-sponsored enterprises, primarily Fannie Mae and Freddie Mac. The Fed had planned to allow the size of that portfolio to shrink gradually over time as the debts matured or were prepaid. Instead, it will use that money to buy longer-term Treasury securities. This largely symbolic action sends a signal that the Fed sees the recovery weakening and that it stands ready to take more aggressive action, if needed, to keep it on track.