We analyze 7.7 million patents via textual analysis to develop a novel patent-to-patent measure of innovation similarity among firms. With this measure, we investigate whether stock price movements reveal information about firms' technological connectedness. We find that investors impound...

When an event is anticipated, the firm's stock return around the announcement of the event may have an inconsistent sign: a positive sign around negative news, or vice versa. We attempt to quantify the frequency of this problem, first with a brief mathematical model and simulation, then with...