Clarke and Statman (1998) analyze how sentiment responds to moves in the market. Keep in mind that bulls forecast that the recent upward trend in the market will continue, while bears and chickens predict that the recent upward trend will reverse. Suppose that during the preceding four weeks the S&P 500 index increased by 1 percent. Clarke and Statman find that this leads to a 1.23 percentage increase in bulls, as some bears and chickens change their perspective. Specifically, the bears decline by 1.18 percent and chickens by 0.05 percent.