I. When the sum of the residuals is greater than zero, the data set is nonlinear. II. A random pattern of residuals supports a linear model. III. A random pattern of residuals supports a non-linear model.
bull market definition. A market, especially a stock market, characterized by rising prices; the opposite of a bear market. We can always go back to worrying; we are still in a bull market for fear.
The bear and bull markets are named after the way in which each animal attacks its victims. It is characteristic of the bull to drive its horns up into the air, while a bear, on the other hand, like the market that bears its name, will swipe its paws downward upon its unfortunate prey.