This study aims to examine the effects of new media and communication tools on investor behavior by integrating communication theories with traditional and behavioral finance approaches. The digital transformation in communication technologies has fundamentally altered the production, circulation, and consumption of information, significantly influencing the functioning of financial markets and investors’ decision-making processes. Social media platforms, digital financial communities, and online information sources have become key determinants shaping investors’ risk perceptions, return expectations, and market attitudes. While traditional finance theory assumes fully rational investors, behavioral finance emphasizes that investors make decisions under bounded rationality and are influenced by psychological and social factors. In this context, new media not only facilitates access to financial information and increases market participation but also amplifies behavioral biases such as confirmation bias, overconfidence, and herd behavior. Within this framework, the study discusses the historical evolution of communication tools, the concepts of network society and new media, and the transformation of finance theory. By reviewing the relevant literature, it evaluates empirical studies that investigate the relationship between new media usage and investor behavior.