One of the logical headaches that we were wrestling with for some time has now been resolved (in theory), using the approach that we have been suggesting for some time.
ESMA put out a Q&A on Friday that explains how the underlying data that defines the EU wide volumes for various instruments will be collected during the first six months of 2018. Given that the Systematic Internaliser regime requires the measurement of thresholds against the previous six months of data, to understand whether a firm is obliged to operate trading for a given instrument under the SI regime, many have been wondering how to approach the initial period of MiFID operation. The period of data collection and explanation from ESMA clarifies this issue and allows for a delayed obligation of the SI regime until 1st September - although pointing out that a voluntary implementation may be appropriate for some firms to meet their wider trading obligations.
One positive outcome of this implementation delay is that the market has a few more months to build their SI infrastructure. One challenge to keep an eye on is that the obligation to operate under the regime potentially hits a firm only one month after the data becomes available.