The Markets in Financial Instruments Directive (Mifid) introduced in 2007 to liberalise trading across Europe spawned unintended consequences, which the current review is seeking to resolve. But that review could itself have unintended consequences in forcing too much transparency onto dark pools, preventing their legitimate use by institutional investors. Vlad Khandros, head of market structure analysis at Liquidnet, explains to Jeremy Grant, that pension and mutual funds are worried their ability to source liquidity and execute orders could be impaired.