Limits to arbitrage play a central role in behavioral finance. They are thought to interfere with arbitrage processes so that security prices can deviate from true values for extended periods of time. We describe a recent financial innovation that allows limits to arbitrage to be sidestepped,...

We analyze dynamic trading by an activist investor who can expend costly effort to affect firm value. We obtain the equilibrium in closed form for a general activism technology, including both binary and continuous outcomes. Variation in parameters can produce either positive or negative...