(9)Competent authorities should be able to react to events known in advance that lead to a change in the number of transactions in a financial instrument whereby the applicable tick size may no longer be appropriate. To that end, a specific procedure should be set out to avoid disorderly market conditions arising from corporate actions that may cause the tick size of one specific instrument to be unsuitable. That procedure should apply to corporate actions that could significantly affect the liquidity of that instrument. While assessing the impact of a corporate action on a specific financial instrument, competent authorities should take account of any previous corporate actions with similar characteristics.