CEOs taking public positions is nothing new, of course. Ben Cohen and Jerry Greenfield made it a part of their namesake ice cream company’s mission to support social causes, and Apple CEO Tim Cook has long made public his support of gay marriage.

But for the most part few people cared about what a CEO thought about non-business issues. As the country has become more polarized, though, CEOs are often pressured to take stands on controversial social and public policy issues, and those positions can financially impact their company.

Michael Durney, assistant professor of accounting in The University of Iowa Tippie College of Business, talked recently with the Iowa Capital Dispatch about how investors factor a CEO’s activism into their decision to buy or sell a stock.

Durney surveyed online stock traders about statements made by the CEO of a fictitious company to determine how investors respond to activist CEOs. The study found that the CEO’s position significantly affected investing decisions. Investors who agreed with the CEO bought stock and investors who disagreed sold stock, a result Durney said is not surprising.

But what surprised him is that when the CEO took no position, investors reacted as positively as they did when they agreed. The silence prompted investors to project their own views onto the CEO, so they believed he shared their values.

Does this mean CEOs should always be neutral? No, Durney says. CEOs should voice what they believe in if there is a change they want to make in the world. But they should recognize that activism will inherently offend a significant number of potential investors, while inactivism not only offends few people, and seems to give investors permission to think the CEO is on their side.