While there is no general consensus about how long the bear market will last, it is expected that prices will continue to fall for a long time. Demand for products on a market under the bear market is declining. Because demand is decreasing, nobody wants to buy those products and prices continue to fall.
The bull market, on the contrary of the bear market, shows that the related market will be on the rising trend for a long time and that the demand for the products in that market is increasing.
If gold prices were to be taken as an example, the bull market was experiencing a rising trend from the beginning of 2000s to the end of 2011 for a long time. However, in the middle of 2013, 2011 peak price level of 1900 dollars ounce of the level of 1500 ounces fell below. There was a decrease of about 30% from the previous peak level and gold prices were officially under the influence of the bull market.