The last fifteen years are characterized by a sharp increase in the share of high-tech companies in terms of attracting investment resources in the world's leading stock markets. High-tech companies over this period significantly outpaced value stocks in terms of return on investment. On the one hand, what is happening is a natural process, since in the face of accelerating industry changes, both in traditional sectors and in sub-sectors of the new economy, there are more opportunities for the emergence of companies with disruptive innovations. High market capitalizations of such companies are a natural metric of fundamental shifts in the economy. On the other hand, the very nature of investment decision-making is changing, since an objective assessment of the intrinsic value of the business of high-tech companies is becoming vaguer, more controversial, dependent on future scenarios, and subject to interpretations. And these interpretations, according to the theory of reflexivity, are increasingly having a feedback effect on fundamentals, especially in high-tech companies.The purpose of this article is to conceptualize a new heuristic model of the “effective interpreter”, which, in the conditions of high reflexivity and narrative contexts of the stock market, has significantly diverged across a number of key attributes from the traditional model of the “rational investor”. The author compares the two models. The process of divergence of the two models occurs under the influence of a number of behavioral heuristics and cognitive biases. At the same time, the author emphasizes that a high narrative component in the value of companies does not always and necessarily mean the predominance of irrationality. Here it is more correct to assume some correlation between the rise of narrative decision contexts and the cognitive challenges of investment decision makers.As one of the possible directions for further research, the author notes the systematization of the main factors of cognitive biases, which seem to make switching to the “effective interpreter” model in portfolio investments in high-tech companies irreversible in the current conditions.