 What about insider trading?

Insider trading refers to the buying or selling of a publicly-traded company's stock or other securities based on material, nonpublic information about the company. It is typically illegal because it violates the principle of fairness in the securities markets, as it gives an unfair advantage to those who have access to confidential information. Material information is defined as any information that could affect an investor's decision to buy or sell a stock, such as earnings reports, mergers and acquisitions, or changes in management.

Insider trading can discourage investment, and cause CEOs to hide information from employees. While there have been arguments that insider trading makes share prices more quickly go to their proper value, the true solution is that if investors dislike insider trading, companies can legally declare that they will only work with those that legally agree not to trade its shares or facilitate insider trading. If someone unaffiliated with the company simply overhears or comes across insider information, this won't stop them, but even if it were illegal, it would be nearly impossible to prove such a case.