Answer: More people put money in stocks hoping to get rich.
Explanation: A bull market is identified by an increase in stock prices. There is high consumer confidence, and people put money in stocks believing that the prices will keep increasing and make them rich. This in turn fuels higher prices as less investors are willing to sell.
The Bear market is the opposite. This is when stocks prices are falling and investors are getting rid of their stocks due to low confidence in the market or a receding economy.