A limited number of about ten stock exchanges dominates the world's financial market places. The New York Stock Exchange has by far the highest market capitalization among these ten trading centers. We may look at the clustering around these market places from two different perspectives: From the perspective of the stock exchange, or from the angle of the firm looking for investors. What we observe is an unprecedented level of competition among stock exchanges. In this continuous struggle only a few stock exchanges will prevail to attract foreign companies, driven by the fact that the stock exchanges? growth can no longer be maintained by domestic companies alone. Which stock exchanges are the most important ones in terms of size? What is the categorization by country of origin? At which stock exchanges can we find the highest number of foreign listings? In the second part of the work we will have a closer look at the perspective of the individual firm. Companies listed on their domestic exchanges seek for a foreign listing for various reasons. Although 90% of the world's companies still list on domestic exchanges, the trend to list on foreign exchanges is persistent.