1. Member States shall require regulated markets to adopt tick-size regimes in shares, depositary receipts, exchange-traded funds, certificates and other similar financial instruments and in any other financial instrument for which regulatory technical standards are developed in accordance with paragraph 4. The application of tick sizes shall not prevent regulated markets from matching orders large in scale at mid-point within the current bid and offer prices.

2. The tick size regimes referred to in paragraph 1 shall:

(a) be calibrated to reflect the liquidity profile of the financial instrument in different markets and the average bid-ask spread, taking into account the desirability of enabling reasonably stable prices without unduly constraining further narrowing of spreads;

(b) adapt the tick size for each financial instrument appropriately.