Using newly-constructed data covering the last decade, we document that, in most of forty markets, when added to the main index, firms' returns experience an increase in comovement with the rest of the index, reflected in higher beta and greater explanatory power of the market return. Stock...

Using newly-constructed data covering the last decade, we document that, in most of forty markets, when added to the main index, firms’ returns experience an increase in comovement with the rest of the index, reflected in higher beta and greater explanatory power of the market return. Stock...