A bull market is when the economy is in good shape, the unemployment rate is low, and stock prices are rising. It's easy to pick stocks during a bull market because everything is going up. Beware that bull markets can't last forever, and sometimes lead to disaster if stocks become overvalued.

A bear market occurs when the economy is in bad shape, recession is impending and stock prices take a dive. It is very difficult to pick high-performing stocks during such a time. However, some investors prefer to purchase stock in a bear market, while the prices are low, and stick with them until the prices go back up.