What constitutes insider dealing?

Insider dealing refers specifically to the buying or selling of shares or securities while in possession of material, non-public information about the issuing company. This practice is illegal because it undermines the integrity of the financial markets, giving unfair advantages to those with access to confidential information. The key element of insider dealing is that the information used for the trading decision is not available to the general public, thus leading to a potential imbalance in the market.

In this context, dealing in shares or securities with insider information directly captures the essence of insider trading. It highlights the misuse of privileged knowledge for personal gain, which is exactly what laws against insider dealing aim to prevent. Each of the other options, while related to the concept of information use in investments, does not accurately reflect the specific legal offense associated with insider dealing. For instance, disclosing confidential information in public would likely lead to a different legal issue concerning the breach of confidentiality rather than insider trading itself. Similarly, investing in real estate or encouraging investments based on publicly available information doesn't fit the definition, as these do not involve the exploitation of undisclosed insider information. Thus, the focus on unlawful trading activities involving unpublicized, material information makes the correct answer distinctly appropriate for the concept of insider dealing.