Despite few transactions being prohibited under the EU Merger Regulation, the Deutsche Börse/NYSE case was blocked earlier this year. The recently published decision suggests misalignment between the parties and DG COMP on three issues: market definition; the relevance of efficiencies; and possible commitments. Given commentators report the parties having to pay breakdown costs exceeding $200 million, as well as the effect on the parties, understanding what were the misaligned issues, and why arose is important.