Weekly returns of stock portfolios exhibit substantial autocorrelation. Analytical studies suggest that nonsynchronous trading is capable of explaining from 5% to 65% of the autocorrelation. The varying importance of nonsynchronous trading in these studies arises primarily from differing assumptions regarding nontrading periods of stocks. We simulate the effects of nonsynchronous trading by sampling stock returns from a return generating process using transactions data to obtain the precise time of each stock's last trade. We find that simulated weekly portfolio returns exhibit autocorrelations that are roughly 25% that of their observed (CRSP) weekly returns.

This study develops a model in which rational issuers maximize the expected surplus from going public by choosing an offer price that weighs the benefit of higher proceeds if the offer is completed against the cost of foregone surplus if the offer fails. Increases in the market valuation of comparable firms during the waiting period imply higher surplus associated with going public; issuers respond with a partial revision in the offer price to elevate the probability of completion. The model offers insights into many facts associated with initial public offering pricing, including partial adjustment to market returns, the inverse relation between withdrawal and market returns, the asymmetric price adjustment to up versus down market returns, hot-issue markets, and unconditional underpricing.