A bear market is a situation on the stock market when people are selling a lot of shares because they expect that the shares will decrease in value and that they will be able to make a profit by buying them again after a short time. Compare bull market. bull market. a situation in which the value of stocks is decreasing. In securities and commodities trading, a declining market. A bear is an investor who expects prices to decline and, on this assumption, sells a borrowed security or commodity in the hope of buying it back later at a lower price, a speculative transaction called short-selling. See also bull market