In trading, the term “bear” is used to refer to an investor who takes a short position. A bear believes that a rate will decrease, and goes short (opens negative positions) to take advantage of rate drops. This is accomplished by borrowing securities and selling them at current prices, then buying those same securities back for less when the price falls and returning them to the lender. In this way, a bear profits when rates go down. A falling rate is referred to as being “bearish”.
The opposite of a bear is a “bull”. Bulls are investors who open a long position, meaning that they believe rates will go up. A bull profits when rates climb.