U.S. stocks rallied today apparently in anticipation of a Federal Reserve announcement to further loosen lending in the U.S. economy.

While there is widespread speculation, it's not certain that Fed will make a major announcement tomorrow. The country's central bank may hold off on a new plan and instead just reiterate a willingness to act if the economy worsens.

It's hard to see how much more of an impact the Federal Reserve can have. Interest rates are already at record lows but banks are still reluctant to lend and companies are still sitting on a lot of cash.

The Fed will also announce a revised forecast for unemployment and GDP growth for the coming months. Somewhat gloomier forecasts won't exactly be a surprise.

Both announcements will come around at 2 P.M. eastern time tomorrow.