‘algorithmic trading’ means trading in financial instruments where a computer algorithm automatically determines individual parameters of orders such as whether to initiate the order, the timing, price or quantity of the order or how to manage the order after its submission, with limited or no human intervention, and does not include any system that is only used for the purpose of routing orders to one or more trading venues or for the processing of orders involving no determination of any trading parameters or for the confirmation of orders or the post-trade processing of executed transactions ;

6. Member States shall require a regulated market to have in place effective systems, procedures and arrangements, including requiring members or participants to carry out appropriate testing of algorithms and providing environments to facilitate such testing, to ensure that algorithmic trading systems cannot create or contribute to disorderly trading conditions on the market and to manage any disorderly trading conditions which do arise from such algorithmic trading systems, including systems to limit the ratio of unexecuted orders to transactions that may be entered into the system by a member or participant, to be able to slow down th ...[+++]e flow of orders if there is a risk of its system capacity being reached and to limit and enforce the minimum tick size that may be executed on the market.

Where any investment firm deploys an algorithmic trading strategy in order to fulfil its obligations as a market maker it shall ensure that the algorithm shall be in continuous operation during the trading hours of the trading venue to which it sends orders or through the systems of which it executes transactions and that the trading parameters or limits of the algorithm shall ensure that the investment firm posts firm quotes at competitive prices with the result of providing liquidity on a regular and ongoing basis to these trading venues at all times regardless of prevailing market conditions unless the written agreement provides other ...[+++]wise .

Furthermore while risks arising from algorithmic trading should be regulated the use of algorithms in post-trade risk reduction services does not constitute algorithmic trading.

3. Member States shall require a regulated market to have in place effective systems, procedures and arrangements, including requiring members or participants to carry out appropriate testing of algorithms and providing environments to facilitate such testing, to ensure that algorithmic or high-frequency trading systems cannot create or contribute to disorderly trading conditions on the market and to manage any disorderly trading conditions which do arise from such algorithmic or high/frequency trading systems, including systems to identify all orders involving high frequency trading, limit the ratio of unexecuted orders to transactions ...[+++]that may be entered into the system by a member or participant, to be able to slow down the flow of orders if there is a risk of its system capacity being reached and to limit and enforce the minimum tick size that may be executed on the market.

30) "Algorithmic trading" means trading in financial instruments where a computer algorithm automatically determines individual parameters of orders such as whether to initiate the order, the timing, price or quantity of the order or how to manage the order after its submission, with limited or no human intervention.