This paper examines the value effects of improvements in the trading mechanism. Selected stocks on the Tel Aviv Stock Exchange were transferred gradually from a daily call auction to a mechanism where the call auction was followed by iterated continuous trading sessions. This event was associated with a positive and permanent price appreciation. The cumulative average market-adjusted return over a period that started five days prior to the announcement and ended 30 days after the stocks started trading by the new method was approximately 5.5%. In addition, we find positive liquidity externalities (spillovers) across related stocks, and improvements in the value discovery process due to the improved trading method. Finally, there was a positive association between liquidity gains and price appreciation.

This paper studies the interaction between dealer markets and a relatively new form of exchange, passive crossing networks, where buyers and sellers trade directly with one another. We find that the crossing network is characterized by both positive (‘liquidity’) and negative (‘crowding’) externalities, and we analyze the effects of its introduction on the dealer market. Traders who use the dealer market as a ‘market of last resort’ can induce dealers to widen their spread and can lead to more efficient subsequent prices, but traders who only use the crossing network can provide a counterbalancing effect by reducing adverse selection and inventory holding costs.