Cramer identified four keys to the market's rebound. First, he said the markets are deeply tied to the European markets.

Second, Cramer said the markets love a weak U.S. dollar.

The third thing that allowed the markets to rally was oil, said Cramer.

Finally, Cramer said copper allowed the markets to rally. Copper, like oil, is a gauge on the growth of China and the rest of the world.

Source: @thestreet.com