We study the dynamics of an innovative industry in which agents learn about the likelihood of negative shocks. Managers can exert risk prevention effort to mitigate the consequences of shocks. If no shock occurs, confidence improves, attracting managers to the innovative sector. But, when confidence becomes high, inefficient managers exerting low risk-prevention effort also enter. This stimulates growth, while reducing risk prevention. The longer the boom, the larger the losses if a shock occurs. Although these dynamics arise in the first-best, asymmetric information generates excessive entry of inefficient managers, earning informational rents, inflating the innovative sector, and increasing its vulnerability.

High speed market connections improve investors׳ ability to search for attractive quotes in fragmented markets, raising gains from trade. They also enable fast traders to obtain information before slow traders, generating adverse selection, and thus negative externalities. When investing in fast trading technologies, institutions do not internalize these externalities. Accordingly, they overinvest in equilibrium. Completely banning fast trading is dominated by offering two types of markets: one accepting fast traders, the other banning them. Utilitarian welfare is maximized with (i) a single market type on which fast and slow traders coexist and (ii) Pigovian taxes on investment in the fast trading technology.

We study the dynamics of an innovative industry when agents learn about its strength, i.e., the likelihood that it gets hit by negative shocks. Managers can exert risk-prevention effort to mitigate the consequences of such shocks. As time goes by, if no shock occurs, confidence improves. This attracts managers to the innovative sector. But, when confidence becomes high, less managers exerting low risk-prevention effort also enter. This accelerates the growth of the industry, while inducing a decline in risk-prevention. The longer the boom, the stronger the confidence, the larger the losses if a shock occurs. While the above dynamics arise in the first best, with asymmetric information there is excessive entry of inefficient managers, earning informational rents at the expense of efficient managers. This inflates the innovative sector and increases its vulnerability.