The recent clarification of the National Securities Market Commission (CNMV), in line with the interpretation of the European stock market supervisor (ESMA), has shed light on the scope of the so -called Blackout Period: that period of silence in which the directors of traded companies are prohibited from operating with their own actions before the publication of results. The CNMV has specified that there must be a single period closed for each financial report – intermedium or annual – that concludes on the date of the announcement of results, not on the formal publication date of the report. Thus, if an entity disseminates an advance of results that includes all the key information, it will be that publication that sets the end of the closed period. From that moment on, managers may operate, provided they are not in possession of privileged information by other relevant operations. This obligation not to operate during the 30 days prior to the publication of financial results, introduced by the Regulation on Market Abuse (MAR), is a measure that was already part of the internal behavior regulations of most entities. It is a consolidated practice that reflects the commitment to the principles of good corporate governance. However, the real problem lies in the fulfillment of the closed periods, but in the improper use of privileged information outside them. Although the CNMV has not imposed to date any sanction for violating the closed period, the panorama changes when it comes to the use of privileged information. In 2024, the agency imposed 51 fines for a total of 12.3 million euros – more than six times the amount of the previous year – and opened 277 files for suspicious operations of market abuse, 13.5% more than in 2023. Of them, 72% were related to the use or attempted use of privileged information. These figures reflect a tightening in the market The importance of guaranteeing equal access to information. According to the European Institute of Financial Markets, cases for the use of privileged information can reduce the liquidity of the affected securities up to 15% in the weeks after the sanction, due to the loss of confidence of institutional investors. This distrust translates into greater volatility and a higher capital cost for the companies involved, which highlights the direct economic impact of these practices on the market.In sum, the true challenge for the markets lies in the prevention and persecution of the improper use of privileged information. The figures of sanctions and files open by the CNMV show that this risk remains in force and that its impact goes far beyond the mere normative infraction: directly affects the confidence of investors, the liquidity and the reputation of the companies. Patricia Muñoz and Virginia González, professors of AFI Global Education.