It was the merger announcement the market had been waiting for. But when the London Stock Exchange Group and Deutsche Börse formally revealed their intention to tie-up on March 16, it was largely confirmation of facts everyone had known for almost a month.

For shareholders' benefit, Carsten Kengeter, the Deutsche Börse chief executive who will become chief executive of the merged company, was explicit - the merger would reduce operating costs by a highly ambitious €450 million a year, helping to create a "Europe-based market infrastructure leader".