Mutual funds typically invest a disproportionately large portion of their portfolio in one industry (main industry). We present a simple theoretical model to demonstrate that better mutual fund managers make larger investments in the important supplier/customer industries related to the main industry. Consistent with our theory, empirical tests on a large sample of mutual funds show that investment in related industries is positively associated with fund performance and plays a more significant role in explaining fund performance than investment in the main industry. Furthermore, the positive relation between main investment and fund performance obtains only when related investment is high.

Costly information acquisition makes it rational for investors to obtain important economic news with only limited frequency or limited accuracy. We show that this rational inattention to important news may make investors over‐ or underinvest. In addition, the optimal trading strategy is “myopic” with respect to future news frequency and accuracy. We find that the optimal news frequency is nonmonotonic in news accuracy and investment horizon. Furthermore, when both news frequency and news accuracy are endogenized, an investor with a higher risk aversion or a longer investment horizon chooses less frequent but more accurate periodic news updates.

Private information imposes a severe trading disadvantage on uninformed traders while at the same time providing firms with valuable signals for investment adjustment. The two forces have opposite impacts on the cost of capital, and the net effect depends on which force dominates. We show that stocks of firms with low flexibility in investment adjustment (“value firms”) command an information premium, whereas stocks of firms with high flexibility in investment adjustment (“growth firms”) deliver an information discount. These results are consistent with the findings that growth firms exhibit stronger investment sensitivity to information in stock prices than value firms.

There is a tenuous link between market efficiency and economic efficiency in that stock prices are more informative when the information has less social value. We investigate this link in the context of CEO turnover. Our theoretical model predicts that, when the board’s monitoring intensity and the informed trader’s information decision are jointly endogenized, stock price informativeness is negatively related to the board’s monitoring effort. Our empirical tests provide supporting evidence for this negative effect. Moreover, using the passage of the Sarbanes–Oxley Act (SOX) as a quasi-natural experiment, we find that SOX, while strengthening corporate governance, has a negative effect on stock price informativeness, especially among firms with complex organizational structures.

Governments can efficiently provide liquidity, as when the banking system is bailed out. We study a model in which not all assets can be used to purchase all other assets at every date. Agents sometimes want to sell projects. The market price of the projects sold depends on the supply of liquidity, which is determined in general equilibrium. While private liquidity provision is socially beneficial since it allows valuable reallocations, it is also socially costly since liquidity suppliers could have made more efficient investments ex ante. There is a role for the government to supply liquidity by issuing government securities.

Using microlevel panel data and a difference-in-differences identification strategy, we study the effect of political uncertainty on household stock market participation. We find that households significantly reduce their participation and reallocate funds to safer assets during periods of increased political uncertainty prior to gubernatorial elections. The decline in participation is related to households’ response to elevated asset risk and their incentive to hedge increased labor income risk. In situations where uncertainty remains high after elections, pre-election reduction in participation is only partially reversed.