Insider trading can only be subject to one type of prosecution, either criminal (by the Public Prosecutor) or administrative (by the AMF) (See Art. L. 465-3-6 of the CMF).

In practice, preliminary investigations are usually carried out by the AMF, and the AMF and the Public Prosecutor will then consult on whether the prosecution should be criminal or administrative in nature:

• as soon as the Public Prosecutor intends to launch a public prosecution, they must notify the AMF, which has two months to confirm whether it intends to initiate proceedings against the same defendant on the same facts;
• if the AMF does not respond or states that it does not intend to initiate proceedings, a public prosecution can be launched;
  
• if the AMF does intend to initiate proceedings and serves a statement of objections, the Public Prosecutor then has 15 days to confirm whether they intend to launch a public prosecution and to refer the case to the Public Prosecutor of the Paris Court of Appeal. If not, the AMF can initiate proceedings;
• the same procedure, with the same timeframe (two months and 15 days) operates where the AMF informs the Public Prosecutor of its intention to initiate proceedings.