You can’t fault them for trying. Since 2000, Germany’s leading stock exchange Deutsche Börse has tried and failed to merge with the New York Stock Exchange, and the London Stock Exchange twice. In 2016 it made a third bid for a €25-billion merger with the LSE. Britain’s decision to leave the European Union complicated its plans, but the exchanges believe they can pull off the marriage despite Brexit. The merged exchanges have the potential to create a needed bridge for financial firms considering moving out of London for the continent in a post-Brexit universe. Regulators in Frankfurt, Brussels and London will determine if the deal flies in 2017.