certain actions to slow down price movements when simple matching of orders would result in price changes greater than exchange-prescribed limits. In their clerical role of matching orders saitoris are somewhat similar to specialists on the NYSE. However, saitoris do not trade for their own accounts and therefore are quite different from either dealers or specialists in the United States. Because the saitoris perform an essentially clerical role, there are no market-making ser- vices or liquidity provided to the market by dealers or specialists. The limit-order book is the primary provider of liquidity. In this regard, the TSE bears some resemblance to the fourth market in the United States in which buyers and sellers trade directly via ECNs or networks such as Instinet or Posit. On the TSE, however, if order imbalances would result in price movements across sequential trades that are considered too extreme by the ex- change, the saitori may temporarily halt trading and advertise the imbalance in the hope of attracting additional trading interest to the "weak" side of the market. The TSE organizes stocks into two categories. The First Section consists of about 1,200 of the most actively traded stocks. The Second Section is for less actively traded stocks. Trading in the larger First Section stocks occurs on the floor of the exchange. The remain- ing securities in the First Section and the Second Section trade electronically.     Globalization of Stock Markets   All stock markets have come under increasing pressure in recent years to make interna- tional alliances or mergers. Much of this pressure is due to the impact of electronic trading. To a growing extent, traders view the stock market as a computer network that links them to other traders, and there are increasingly fewer limits on the securities around the world in which they can trade. Against this background, it becomes more important for exchanges to provide the cheapest mechanism by which trades can be executed and cleared. This ar- gues for global alliances that can facilitate the nuts and bolts of cross-border trading, and can benefit from economies of scale. Moreover, in the face of competition from electronic networks, established exchanges feel that they eventually need to offer 24-hour global mar- kets. Finally, companies want to be able to go beyond national borders when they wish to raise capital. Merger talks and strategic alliances blossomed in 2000; although it is still too early to predict with confidence where these will lead, it seems possible that at least two global net- works of exchanges are emerging. One might be led by the NYSE in conjunction with Tokyo and Euronext (which itself is the result of a