insider dealing Dealing by insiders in current, listed securities of a company, using confidential information likely to affect their market value. Generally it is prohibited: Insiders include a person who, within the preceding six months has been knowingly connected with the company and has unpublished, price-sensitive information relating to the securities, and any person who has contemplated a take-over involving the company and is in possession of such information, s. 1. Under s. 2, specified individuals (e.g., some public servants) are prohibited from abusing information obtained in their official capacity.