DOI: 10.52340/ekonomisti.2026.01.20

Annotation. This paper analyzes classical, neoclassical, behavioral, and adaptive theories of capital market development in the post-Soviet context and proposes an integrated framework. The framework interprets historical market evolution, links theories to stage-specific challenges and constraints, and highlights practical applications for investment, policy, and risk management decisions in post-Soviet economies.

Key words: capital market, market evolution, theoretical foundation of market development, post-Soviet economies. 

Introduction

The theoretical foundation of capital market development comprises a complex system of economic and financial theories that explain market functioning, principles of efficiency, and the market’s role in economic development (OECD, 2023). In the post-Soviet space, the development of capital markets faces particular challenges, related to the rapid transition from centrally planned economies, the lack of strong institutional frameworks, limited regulatory experience, and an underdeveloped investment culture (WB, 2023). Accordingly, understanding capital market development in post-Soviet countries requires analyzing existing theories and approaches within specific historical, institutional, and economic contexts. Empirical investigations on this subject remain scarce; therefore, the present study seeks to critically examine theoretical models of capital market development, with a focus on their applicability and relevance within the post-Soviet context.

Capital Market Theories Through the Prism of Post-Soviet Economies

The evolution of capital market theories can be divided into four main stages, which correspond to the development of capital markets in the post-Soviet space (Diagram 1). 

Diagram. Theory Evolution and Post-Soviet Market Development Stages

Sources: Authors’ compilation; diagram created with AI-assisted design 

The initial stage is based on classical and neoclassical financial approaches, which emphasize the importance of liquidity, investor expectations, and uncertainty in financial decision-making (Keynes, 1936). These approaches are particularly relevant for the early stage of post-Soviet markets, when institutional frameworks were not yet established, financial culture was weak, and capital mobilization and resource allocation were severely limited.The second stage is dominated by fundamental models of modern financial economics, such as portfolio theory (Markowitz, 1952), the Capital Asset Pricing Model – CAPM (Sharpe, 1964; Lintner, 1965; Mossin, 1966), and the Efficient Market Hypothesis (Fama, 1970), which provide an analytical framework for systematic risk and expected returns on assets. This stage corresponds to the transitional phase in post-Soviet markets, when institutional capacity improves, market depth increases, and investor decision-making becomes more structured.The third stage includes multifactor asset pricing models and arbitrage pricing theory (Ross, 1976; Fama & French, 1993; Carhart, 1997), as well as methodologies for valuing derivative instruments (Black, Scholes, Merton, 1973), enabling a more realistic analysis of sources of systemic risk, market dynamics, and the growth of institutional capacity. This stage is especially important for post-Soviet economies, at a time when markets gradually move toward structured and regulated systems. The fourth stage focuses on behavioral finance, institutional factors, and adaptive approaches (Kahneman & Tversky, 1979; Lo, 2004; Baker & Wurgler, 2007), allowing for an in-depth analysis of market development in environments where economic, psychological, and institutional factors strongly interact.

Having outlined the four overarching stages in the evolution of capital market theories and their relevance to post-Soviet markets, we proceed to a detailed analysis of each stage, beginning with the foundational early theories.

First Stage – Early Theories.Early capital market theories represent fundamental analytical frameworks that defined the core concepts of capital markets and their principles of functioning. Fishers theory of interest rates focuses on the interrelationship between time and consumption choices and can be applied to study capital allocation issues during the early stage of post-Soviet markets (Fisher, 1930). Keyness Liquidity Preference Theory (LPT) emphasizes investors preference for liquid assets under conditions of uncertainty, which was especially relevant for the early post-Soviet market stage (Keynes, 1936).Markowitzs Portfolio Theory provides an analytical tool for optimal diversification and demonstrates how the trade-off between risk and expected return can guide investment decisions despite limited information. In the early post-Soviet economy, investors faced particular challenges due to constrained infrastructure and informational asymmetry (Markowitz, 1952). Arrow-Debreus general equilibrium model and Modigliani-Millers theorem (1958) provide a normative framework for optimal resource allocation and firm valuation, offering a highly valuable theoretical foundation for analyzing market liberalization and corporate finance. However, their key assumptions—perfect information and market completeness—often do not reflect the realities of post-Soviet economies, characterized by institutional difficulties and informational asymmetry (Arrow & Debreu, 1954; Modigliani & Miller, 1958). Tobins theoretical framework enhances the macroeconomic understanding of capital markets, allowing an assessment of how monetary policy can stimulate capital accumulation and investment activity, particularly in early-stage markets where institutional and regulatory mechanisms are still absent. Thus, it can serve as a primary analytical tool for studying the macroeconomic dynamics of post-Soviet capital markets (Tobin, 1963).

Second Stage – Modern Financial Economics Models. With the evolution of post-Soviet markets, theories of asset pricing and market efficiency become increasingly important in analyzing capital market development. The CAPM model, developed by Sharpe (1964), Lintner (1965), and Mossin (1966), provides a formal framework for the relationship between systematic risk and expected asset returns, serving as a key tool for assessing investment opportunities.

Although the models core assumptions (rational investors, competitive markets, and normally distributed expected returns) were often violated in early post-Soviet environments, it remains widely used for determining the cost of risk and analyzing optimal portfolio construction, especially in early-stage markets characterized by informational asymmetry, weak institutions, and underdeveloped financial culture (Sharpe, 1964; Lintner, 1965; Mossin, 1966). Black further developed a modification of the CAPM, known as the Zero-Beta CAPM, which adapts better to real-world markets with limited borrowing capacity (Black, 1972).Famas Efficient Market Hypothesis (EMH), despite its idealized assumptions of informational efficiency, allows empirical evaluation of market development, particularly in countries where capital markets are initially inefficient and subject to pricing anomalies (Fama, 1970).The option pricing model developed by Black, Scholes, and Merton provides a significant analytical framework for valuing financial instruments and derivative assets. This approach enables the assessment of multiple sources of systemic risk and the dynamics of financial instruments in the market. Its practical significance grows with institutional development, strengthened regulatory frameworks, and increased market depth, providing a methodological foundation for post-Soviet financial institutions, particularly in financial risk assessment and management (Black, Scholes, & Merton, 1973).Rosss Arbitrage Pricing Theory (APT) is another crucial analytical tool that enables simultaneous analysis of multi-asset portfolio risk and expected return. It is particularly relevant for rapidly developing and transitional markets, such as post-Soviet economies, where price imbalances, informational asymmetry, and currency volatility create significant challenges for strategic investment and portfolio optimization (Ross, 1976).

Third Stage – Multifactor, Derivative, and Structural Models.Behavioral and institutional theories provide enhanced explanations, especially in contexts where classical assumptions of rationality and informational symmetry are violated. Kahneman and Tverskys Prospect Theory illustrates how post-Soviet investors overreacted to gains and losses, creating speculative bubbles, herding behavior, and market instability (Kahneman & Tversky, 1979).Diamonds Theory of Financial Intermediation highlights the role of banks and financial institutions in reducing informational asymmetries and mobilizing capital, which was particularly important in newly liberalized post-Soviet economies with weak market infrastructure (Diamond, 1984).

Research on market microstructure by Kyle, Glosten & Milgrom, and O Hara illustrates the processes of price formation and liquidity provision, showing how transaction costs, market weaknesses, and uneven information dissemination shape early trading dynamics (Kyle, 1985; Glosten & Milgrom, 1985; OHara, 1995).Fama and French (1993) and Carhart (1997) multifactor models provide additional analytical precision by incorporating size and value factors, explaining structural inefficiencies during the transitional phase (Fama & French, 1993; Carhart, 1997).

Fourth Stage – Evolutionary, Adaptive, and Behavioral Approaches.Evolutionary and adaptive approaches, including Mandelbrots Fractal Market Hypothesis and Los Adaptive Market Hypothesis, recognize market efficiency and behavior dynamics as evolutionary processes shaped by learning, competition, and technological innovation. These frameworks are particularly relevant in the post-Soviet context, where initial instability gradually evolved into more structured, adaptive, and institutionally resilient financial systems (Mandelbrot, 1997; Lo, 2004).

The Capital Structure Substitution Theory (CSST), developed by Robert Morley, focuses on shareholder income maximization and the effects of capital structure changes on stock prices. Its applicability in post-Soviet markets is limited by institutional weakness, low liquidity, informational asymmetry, and insufficient regulatory monitoring, which constrain the effectiveness of capital structure adjustments.Baker and Wurglers research further strengthens this perspective, emphasizing the impact of investor psychology, speculative waves, and socio-economic expectations on market behavior (Baker & Wurgler, 2007).

In the post-Soviet context, classical and neoclassical theories are important for understanding liquidity preferences, the interaction between interest rates, savings, and investments, which facilitates the planning of monetary policy and early investment strategies. Portfolio theory, the Capital Asset Pricing Model (CAPM), and multifactor models optimize asset allocation and evaluation from the perspective of systemic risk, while efficient market hypotheses assess informational efficiency and price anomalies. Behavioral finance, sentiment-based models, and market microstructure models explore investors psychological factors, speculative cycles, and liquidity constraints, contributing to risk management and market design.  Thus, no single theory is sufficient on its own to explain the trajectory of post-Soviet capital market development.

A Multi-Theoretical Framework for Investment and Policy Decisions in Post-Soviet Markets

We developed a multi-theoretical, integrated framework that synthesizes classical, neoclassical, adaptive, and behavioral models. This framework highlights the relevance of these theories for post-Soviet markets and maps them onto the specific challenges at each stage of market development (see Table), providing a foundation for practical application. 

Table. Multi-Theoretical Framework for Post-Soviet Markets

Source: Compiled by the authors from multiple sources (see references). 

Beyond demonstrating theoretical applicability, the framework guides investment decisions, policy design, risk management, and market structure development. It also offers a structured approach for analyzing how markets may respond to technological, regulatory, and macroeconomic changes, supporting informed strategic planning and potential forecasting of market evolution.

Limitation and Future Research. Despite its comprehensive scope, this framework has certain limitations. Post-Soviet economies are highly heterogeneous; for example, the Baltic states differ significantly from Central Asian republics, so the frameworks applicability may vary across countries. Some theoretical assumptions, such as perfect information or market efficiency, may not fully capture the realities of transitional markets. Additionally, the framework remains largely conceptual, with limited empirical testing in real-world post-Soviet contexts. Future research could address these gaps by empirically validating the framework in specific countries and exploring how local factors shape capital market development.

Conclusion

The integrated, multi-theoretical framework developed in this study offers a coherent lens to understand the complex dynamics of post-Soviet capital markets. By bridging diverse theoretical perspectives with practical considerations, it provides both policymakers and investors with a tool to navigate transitional market challenges. Beyond its immediate applicability, the framework establishes a foundation for future empirical research and strategic analysis, highlighting how evolving technological, regulatory, and economic factors may shape market trajectories. Its adoption can enhance informed decision-making and support the sustainable development of emerging financial markets. 

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