Traders can go short at the bid price.

The terminology is from the broker point of view, they are bidding to buy from you.

A Bear Market occurs when the price of a security is falling, and the negative outlook of the security causes the security’s price to continue to fall, causing a self-sustaining problem.

For a downturn like this to be officially considered a bear market, it must be on-going for longer than two months, otherwise it is known as a correction.

Bears are generally traders with a pessimistic view on markets that look to profit from a decline in prices.