A Bias in Closing Prices: The Case of the When-Issued Pricing Anomaly

Abstract

Financial studies examining stock price behavior have principally relied on end-of-day data. This paper illustrates a bias in closing prices by reexamining the when-issue pricing anomaly with intraday data. With intraday data, major portions of the pricing anomaly can be explained by: a nonsynchronous matching of trades; a difference in the settlement procedures (labeled time value of money in Choi and Strong (1983)); a mismatching of market purchases with market sales (first proposed by Lamoureux and Wansley (1989)); and a higher frequency of market purchases relative to market sales. In addition, the small remaining portion of the anomaly cannot be arbitraged. The remaining premium is attributed to a lower level of limit order competition and an order imbalance in the when-issued shares.