The competent authorities shall require for each instrument at least: (a) publication at the start of each day's trading on the market of the weighted average price, the highest and the lowest prices and the volume dealt in on the regulated market in question for the whole of the preceding day's trading; (b) in addition, for continuous order-driven and quote-driven markets, publication: - at the end of each hour's trading on the market, of the weighted average price and the volume dealt in on the regulated market in question for a six-hour trading period ending so as to leave two hours' trading on the market before publication, and - every 20 minutes, of the weighted average price and the highest and lowest prices on the regulated market in question for a two-hour trading period ending so as to leave one hour's trading on the market before publication.
