Time of publication

All market participants must have the same opportunity to take notice of potentially price-sensitive facts. When selecting the time of publication of notices with potentially price-sensitive content, certain provisions must therefore be observed.


As soon as an issuer has knowledge of the main points of a potentially price-sensitive fact, it must publish this fact in line with the provisions on ad hoc publicity. In relation to the time of publication, however, it is important to differentiate whether the ad hoc publication should or must take place outside critical trading hours (principle) or during critical trading hours (exception). Depending on the pertinent time of publication, the publication of an ad hoc notice must follow other specific procedures.

Publication times for ad hoc notices


Ad hoc notices must be published where possible outside critical trading hours, which begin 90 minutes before start of trading and end at close of trading, i.e. before 7.30 am and after 5.30 pm. This gives information recipients enough time to read and interpret an ad hoc notice.

When an ad hoc notice is published, SIX Exchange Regulation must in all cases be notified immediately, i.e. no later than when the information is made public.


In special cases, where an ad hoc notice must be published during critical trading hours, i.e. from 90 minutes before start of trading to close of trading, SIX Exchange Regulation must be notified of the ad hoc notice no later than 90 minutes before the planned publication. This gives SIX Swiss Exchange the possibility to temporarily suspend trading in the relevant shares in exceptional situations. In case it is not clear how a forthcoming publication should be handled, SIX Exchange Regulation must be contacted as soon as possible.


Special arrangement: Postponement of disclosure and information leaks

Under certain conditions, publication of an ad hoc notice may be postponed (e.g. in the run-up to a takeover). If, however, the confidentiality of a potentially price-sensitive fact can no longer be ensured, this is known as an information leak. Where possible, publication should not be postponed or should only be postponed for a short time in order to prevent information leaks.

If an information leak occurs, the obligation to publish the potentially price-sensitive fact under the ad hoc publicity provisions must be immediately discharged. The public must be immediately informed of the hitherto confidential potentially price-sensitive fact – even if publication was scheduled for a later time. Where the public must be informed during critical trading hours, SIX Exchange Regulation must be immediately contacted by telephone so that further action can be discussed.


Commentary / Guideline

Commentary on the Directive on Ad hoc Publicity

Commentary on the Directive on Ad hoc Publicity (DAH Commentary), Completely revised version as of 1 November 2011