Generex Biotechnology Corp explained the sharp decline of its stock price on Monday by a decision of several leading drugmakers to stop developing inhaled insulin products.

When TV viewers like a company's Super Bowl commercial, the company's stock price goes up, according to a study by researchers in the University at Buffalo School of Management and Cornell University.

It has been an indecisive session on Wall Street with a late plunge in the market sending stock prices sharply lower. A rebound in crude oil prices has sent big energy issues like Exxon Mobil higher, but it has hurt large manufacturers, including Caterpillar.

Corporate leaders at Dow Chemical, Cracker Barrel and Eastman Kodak have learned the hard way that public protests can drive down the value of an otherwise healthy stock.