Purpose The purpose of this study is to measure financial inclusion (FI) and to examine the role of digital financial literacy (DFL) and its components, and various socio-demographics in relation to FI. In addition, the mediating effect of digital financial attitudes (DFA) on the relationship between digital financial knowledge (DFK) and digital financial behaviour (DFB), as well mediating effect of DFA and DFB on the relationship between DFK and FI, is being explored.Design/methodology/approach Using a cross-sectional research design, we utilize a dataset from the survey of adults’ financial literacy in Bosnia and Herzegovina, collected from the representative sample of 1,096 adults in 2022. The main methodology relies on logistic and ordinal logistic regression analyses and PROCESS for mediation analyses.Findings The findings suggest that the effect of DFK on DFB is partially mediated by DFA. In addition, the effect of DFK on FI is fully mediated through three pathways: DFA, DFB, and DFA and DFB in serial mediation. Age, education, employment status and residence are significantly related to FI. Internet access is significant only for FI scores but not for adults’ banking status. Although women are almost twice as unbanked as men, we find no gender-based differences in financial product holdings, FI or adults’ banking status.Practical implications There is a need to enhance DFK and DFA to enable adults to use financial products. Financial institutions could use our results in designing and promoting their services.Social implications Policy implications are seen in the need for developing national strategies for financial education, with an emphasis on strengthening DFL, especially DFK and DFA, which will enhance the formal FI of adults. Also, governments should work on expanding Internet access.Originality/value The results make a contribution to the theory of planned behaviour. They contribute to the limited empirical evidence of the mediating role of DFA in relationship to DFB, as well as the mediating role of DFA and DFB in relationship to FI.

Using extensive and comprehensive databases to select a subset of research papers, we aim to critically analyze previous empirical studies to identify certain patterns in determining the optimal number of stocks in well-diversified portfolios in different markets, and to compare how the optimal number of stocks has changed over different periods and how it has been affected by market turmoil such as the Global Financial Crisis (GFC) and the current COVID-19 pandemic. The main methods used are bibliometric analysis and systematic literature review. Evaluating the number of assets which lead to optimal diversification is not an easy task as it is impacted by a huge number of different factors: the way systematic risk is measured, the investment universe (size, asset classes and features of the asset classes), the investor’s characteristics, the change over time of the asset features, the model adopted to measure diversification (i.e., equally weighted versus optimal allocation), the frequency of the data that is being used, together with the time horizon, conditions in the market that the study refers to, etc. Our paper provides additional support for the fact that (1) a generalized optimal number of stocks that constitute a well-diversified portfolio does not exist for whichever market, period or investor. Recent studies further suggest that (2) the size of a well-diversified portfolio is larger today than in the past, (3) this number is lower in emerging markets compared to developed financial markets, (4) the higher the stock correlations with the market, the lower the number of stocks required for a well-diversified portfolio for individual investors, and (5) machine learning methods could potentially improve the investment decision process. Our results could be helpful to private and institutional investors in constructing and managing their portfolios and provide a framework for future research.