Wednesday, April 23, 2008

'Bear Raid' Stock Manipulation: How and When It Works, and Who Benefits

From Knowledge@Wharton:

When Bear Stearns collapsed in March, some insiders argued it was wrong to blame the firm's risky bets on mortgaged-backed securities. They had another culprit: malevolent traders working together in the upside-down world of short sales -- making money by knocking down Bear's stock.

No one openly admits to conducting a "bear raid," since deliberately manipulating stock prices is illegal. But Wall Street has long believed bear raids can and do take place. There has, however, been little academic research to explain the forces at work. Now two finance experts have shed some light on the process. "We basically describe a theory of how bear raid manipulation works," says Wharton finance professor Itay Goldstein. He and Alexander Guembel of the Saïd Business School and Lincoln College at the University of Oxford describe the procedure in their paper titled, "Manipulation and the Allocational Role of Prices."

Their key finding illuminates the interplay between a firm's real economic value and its stock price, showing how traders who deliberately drive the share price down can undermine the firm's health, causing the share price to fall further in a vicious cycle....MORE