A new breed of activism

•Large activists prefer to target firms that other activists are already targeting.•The frequency of these campaigns has been stable over our sample period.•These campaigns are more prevalent when the activists have similar objectives.•These campaigns are more likely if the first activist produce low or high returns. This paper examines shareholder activism campaigns where multiple large activists concurrently target the same firm. We document that activists prefer to target firms that other activists are already targeting, and that the frequency of these campaigns has been stable over our sample period. This phenomenon is most prevalent within six months of the arrival of the initial activist, when the activists pursue similar strategies, and when the initial activist generates very low or high returns. These results help increase understanding of this new breed of activism.