Quotes, Order Flow, and Price Discovery

The goal of this paper is to examine the impact of the 1975 Congressional mandate to integrate the trading of NYSE-listed stocks. The conclusions are: Most of the time, the NYSE quote matches or determines the best displayed quote, and the NYSE is the most frequent initiator of quote changes. Non-NYSE markets attract a significant portion of their volume when they are posting inferior bids or offers, indicating they obtain order flow for other reasons, such as quot;payment order flow.quot; Yet, when a non-NYSE market does post a better bid or offer, it does attract additional order flow