Recital 67

In order to ensure effective supervision and in order to enable the competent authorities to take appropriate measures against defective or rogue algorithmic strategies in due time it is necessary to flag all orders generated by algorithmic trading. By means of flagging, competent authorities should be enabled to identify and distinguish orders originating from different algorithms and to reconstruct efficiently and evaluate the strategies that algorithmic traders employ. This should mitigate the risk that orders are not unambiguously attributed to an algorithmic strategy and a trader. The flagging permits the competent authorities to react efficiently and effectively against algorithmic trading strategies that behave in an abusive manner or pose risks to the orderly functioning of the market.