European case law distinguishes between an anticompetitive exchange of information per se and one that falls under prohibition because it is the means of facilitating another restrictive  agreement.

Exchanges of information on prices or any other strategic information are prohibited because they prevent operators from having a normal understanding of the conditions of competition in a market that has become overly transparent. An exchange of information which relates to confidential, specific and current data, takes place with a certain regularity and periodicity, concerns a limited number of operators and occurs on a highly concentrated market is likely to fall foul of the prohibition of Article 101(1) TFEU. The most recent case law even characterizes exchanges of information concerning the participants’ pricing strategies as restrictions by object.

An exchange of information that underpins another anticompetitive mechanism is also contrary to Article 101 TFEU, in particular when it is ancillary to a market-sharing agreement or an agreement on prices and/or quotas.

It is not necessary for the exchange of information to be reciprocal in order to undermine the principle of autonomous market conduct, as long as the disclosure of sensitive information, by reducing uncertainty as to the future conduct of the competitor, directly or indirectly influences the strategy of the receiver of the information.

Consistent with previous case law, the Guidelines for Horizontal Cooperation Agreements set out the general principles for the assessment of exchanges of information. They distinguish between data that can be directly shared between competitors and data that can be shared indirectly through a common agency or a third party (pt 55). Information exchanges are a common feature of many competitive markets and may generate various types of efficiency gains in particular by solving problems of information asymmetries or enabling undertakings or consumers to make cost savings (pt 57). They produce restrictive effects in situations where they increase market transparency enabling undertakings to be aware of market strategies of their competitors (pt 58). They can therefore lead to collusion in the market (pt 66) and allow undertakings to monitor  whether other companies are deviating from the collusive outcome (pt 67) or limit market entry (pt 68). An exchange of information can also lead to anticompetitive (pt 69) and market foreclosure (pt 70). To produce a restrictive effect, the exchange of information must concern undertakings holding a sufficiently large share of the relevant market (pt 87). In any case, restrictions going beyond what is necessary to achieve the efficiencies generated by the exchange cannot benefit from an exemption under Article 101(3) (pts 101 et seq.).