Picture a broker trying to benchmark the performance of a trade in Europe. Easy – unless the only source of price information was old-fashioned paper ticker tapes pouring in from every venue across the European Union. True, brokers no longer have a tangle of paper piling up on the office floor. What they face, however, is the electronic equivalent.

Seven years since EU regulation opened up European stock exchanges to competition, it is still not possible to get a full picture of price information across the continent's market. This is despite repeated industry efforts to consolidate the data stream from Europe's markets into a single "tape".