The claim came as the AFME released research that it said revealed the true size of the European OTC equity market is less than half what is currently reported.
Following the financial crisis, regulators are taking steps to force OTC trades on to exchanges in order to improve transparency and remove counterparty risk.
In its report entitled The Nature and Scale of OTC Equity Trading in Europe, the AFME said that OTC share trading in Europe accounts for 16% of total trades and not 40% as widely reported.
The discrepancy is due to the failure of MiFID's reporting processes to differentiate between genuine and technical trading leading to many trades being counted more than once.
Christian Krohn, a managing director of Equities at the Association for Financial Markets in Europe said: “MiFID has transformed the European equity market landscape but the current reporting requirements cause confusion and can result in misleading claims, as our research shows. This is of concern as it suggests that policy decisions are driven by misinformation or misunderstanding.”
“In light of the ongoing MiFID Review and regulatory proposals around OTC trading, it is critical that policy makers have a full and accurate understanding of the nature and scale of the OTC market.”
The organisation said that more “granular and standardised” reporting requirements would address provide much needed clarity on all OTC equity trades.