Why does shareholder protection matter for abnormal returns after reported insider purchases and sales?

We use a unique data set of more than 240,000 reported insider transactions across 15 European countries and the USA to analyze the link between country-level shareholder protection and abnormal returns following insider trades. We show that abnormal returns after insider transactions are positively correlated with country-level shareholder protection against expropriation by corporate insiders, which supports the information-content hypothesis. Market reaction to insider purchases increases with shareholder protection because shareholder protection enhances the transparency and trustworthiness of insiders’ actions, and limits possibilities for direct profit diversion, so that more information is eventually reflected in stock prices. For insider sales, shareholder protection decreases their negative information content. We conjecture that this is due to the effect of greater transparency and trustworthiness strengthening the diversification and liquidity reasons for selling in better shareholder protection countries. We find limited support for the rent-extraction hypothesis that conjectures that shareholder protection is associated with insider trading dollar profits.