درخت حوزه‌های تخصصی

The present study investigated weak-form market information efficiency in Tehran security exchange (TSE) as an emerging market and in Dow Jones United States security exchange (DJUS) as a developed market based on random walk model. In each market, the random walk model was examined using daily and monthly returns of a set of indices. The results of the parametric and non-parametric tests indicated that the daily returns are not independent and identically distributed in TSE. Moreover, according to the results of the variance ratio test, a trending behavior in daily returns and mean-reversion behavior in monthly returns were observed. In DJUS, however, the daily returns were found to be independent and identically distributed and the results of variance ratio test did not confirm that the returns follow a particular pattern in this market.

This research uses a fuzzy Delphi approach to identify the dimensions and components of investor risk and financing for IT-based startup companies. The statistical population for this study consisted of 30 experts and university professors familiar with the research concepts surveyed to select the dimensions and components identified from the literature and prior research. The results from the fuzzy Delphi method showed that the financing and investor risk dimensions were selected in 9 dimensions and 29 components. The weighting results for the research dimensions and components using the Best-Worst Method (BWM) prioritized each. The weighting results indicate that the industry status ranked first, followed by scientific factors and other components, ranked third to ninth in the LINGO software. Additionally, the intensity of relationships among the research dimensions was assessed using the Decision-Making Trial and Evaluation Laboratory (DEMATEL) technique. The analysis of the intensity of relationships among the dimensions shows that the government factors dimension had the highest numerical value based on the row sum, making it the most influential dimension among those examined in financing startup companies using the DEMATEL technique. Conversely, based on the D-R analysis, the geographic factors dimension received the lowest value and was recognized as the most affected dimension. Using the fuzzy Delphi method, this research has identified specific and novel dimensions and components, such as governmental, geographical, and scientific factors, which have been less addressed in the existing literature.