The CE could be there for a number of reasons - none good. According to OTC Markets, they apply the CE for any one of the following reasons: https://www.otcmarkets.com/glossary#caveat-emptor Buyer Beware. There is a public interest concern associated with the company, which may include a spam campaign, questionable stock promotion, known investigation of fraudulent activity committed by the company or insiders, regulatory suspensions, or disruptive corporate actions. So yes, since MPIX was the subject of past securities violations/fraudulent activities, the CE could be there because of that.