Have you heard of “bear jobbers”? People called them “bears” for short. They would sell the fur of bears for the trappers, often before they had received the pelts. This means they were effectively short-selling pelts. They kept the profits on the spread of what they sold the pelts for versus their costs. This is one source people cite as to why we call it a bear market to this day.
Another source of these terms comes from the bull and bear blood sports popular in the 1800s in California. They would leash a bull and bear together loosely and have them fight brutally, often after Sunday church services. Either could win, but the bears took more victories. Considering these origins, it is easy to imagine choosing the bull as the opposite type of market to bear.
The simplest and most common origin for these names comes from their methods of attack. A bull lowers its head and then thrusts it upwards to attack, and a bear raises up and attacks with downward claw strikes.
This naming trend continues today in Chicago’s major league teams. Since the city is a major hub of market speculation, the list includes the Bears, the Cubs, and the Bulls.