A bull is an investor or trader who expects the price of an asset, or of the market as a whole, to rise. Bulls buy and hold assets, add to positions on dips or use options and futures that profit from gains. Their outlook is described as bullish, and a sustained rise of around 20% or more from a recent low is called a bull market. The opposite is a bear, who expects prices to fall. A common explanation of the name is that a bull attacks by thrusting its horns upwards, while a bear swipes its paws downwards, and both terms were in use in London markets by the eighteenth century. In crypto, a strong, extended rise is often called a bull run.