Stock-market trading is increasingly dominated by sophisticated professionals, as opposed to individual investors. Will this trend ultimately lead to greater market efficiency? I consider two complicating factors. The first is crowding—the fact that, for a wide range of “unanchored” strategies, an arbitrageur cannot know how many of his peers are simultaneously entering the same trade. The second is leverage—when an arbitrageur chooses a privately optimal leverage ratio, he may create a fire-sale externality that raises the likelihood of a severe crash. In some cases, capital regulation may be helpful in dealing with the latter problem.

ABSTRACT Stock‐market trading is increasingly dominated by sophisticated professionals, as opposed to individual investors. Will this trend ultimately lead to greater market efficiency? I consider two complicating factors. The first is crowding—the fact that, for a wide range of “unanchored” strategies, an arbitrageur cannot know how many of his peers are simultaneously entering the same trade. The second is leverage—when an arbitrageur chooses a privately optimal leverage ratio, he may create a fire‐sale externality that raises the likelihood of a severe crash. In some cases, capital regulation may be helpful in dealing with the latter problem.

I identify three option exercise strategies executives engage in, including (i) exercising with cash and immediately selling the shares, (ii) exercising with cash and holding the shares, and (iii) delivering some shares to the company to cover the exercise costs and holding the remaining shares. Stock price patterns suggest executives manipulate option exercises. They use private information to increase the profitability of all three strategies, and likely backdated some exercise dates in the pre-Sarbanes-Oxley period to enhance the profitability of the latter two strategies, where the executive's company is the only counterparty. Backdating is associated with reporting of internal control weaknesses.

ABSTRACT I model strategic interaction among issuers, underwriters, retail investors, and institutional investors when the secondary market has limited price transparency. Search costs for retail investors lead to price dispersion in the secondary market, while the price for institutional investors is infinitely elastic. Because retail distribution capacity is assumed to be limited for each underwriter‐dealer, Bertrand competition breaks down in the primary market and new issues are underpriced in equilibrium. Syndicates emerge in which underwriters bid symmetrically, with quantities allocated internally to efficiently utilize retail distribution capacity.

ABSTRACT I quantitatively measure the interactions between the media and the stock market using daily content from a popular Wall Street Journal column. I find that high media pessimism predicts downward pressure on market prices followed by a reversion to fundamentals, and unusually high or low pessimism predicts high market trading volume. These and similar results are consistent with theoretical models of noise and liquidity traders, and are inconsistent with theories of media content as a proxy for new information about fundamental asset values, as a proxy for market volatility, or as a sideshow with no relationship to asset markets.

ABSTRACT This paper asks how well different organizational structures perform in terms of generating information about investment projects and allocating capital to these projects. A decentralized approach‐with small, single‐manager firms‐is most likely to be attractive when information about projects is “soft” and cannot be credibly transmitted. In contrast, large hierarchies perform better when information can be costlessly “hardened” and passed along inside the firm. The model can be used to think about the consequences of consolidation in the banking industry, particularly the documented tendency for mergers to lead to declines in small‐business lending.

Equity financing is modeled when cash flows and asset values are not verifiable. Investors have enforceable property rights to the firm's assets, but cannot prevent insiders (managers or entrepreneurs) from capturing cash flow. Insiders must coinvest and pay in each period a dividend sufficient to ensure outside investors' participation for at least one more period. Intervention by the investors must be limited by an agreement with insiders or by costs of collective action. Basic models are extended to show why firms go public and why agency costs necessarily arise when the act of investment is not immediately verifiable.