Financial markets reflect the economic activity of nations, industries, companies, and societies. The housing market crash, COVID-19 pandemic, the recent high inflation indexes, and cryptocurrency frenzy illustrate the decisive influence of such systems in modern culture. This work employs the majority-vote opinion model within the complex network's framework to describe financial index evolution in stock markets. The majority-vote dynamics consist of a multi-state opinion formation model proposed to investigate and comprehend collective social phenomena under the effects of a social noise parameter. This work considers that a financial market mainly comprises two categories of investors: noise traders and fundamentalists – the former invest based on their acquaintances, while the latter act based on the market index. The model reproduces real-world market features for a finite level of social anxiety, denoted by a social temperature, and for a small number of interacting fundamentalist agents in random networks.