Introduction: One of the most important challenges for start-up businesses is securing financial resources. Crowdfunding is one of the new methods of entrepreneurial financing, the success of which depends on the behavior of investors, the crowdfunding platform, and the project owners. The purpose of this study is to identify and prioritize the factors affecting the participation of individual and institutional investors in crowdfunding projects.

Methodology: A combined (qualitative-quantitative) approach was used to identify the influencing factors. Accordingly, in the qualitative part, the initial factors were identified by studying theoretical literature and research background and then interviewing experts. In the quantitative part, the final influencing factors were identified and ranked using a Delphi-fuzzy survey strategy.

Findings: The results identify 22 basic themes organized into 5 themes: entrepreneur characteristics, project characteristics, crowdfunding platform characteristics, investor characteristics, and macroeconomic environment as primary influencing factors. Finally, 21 themes were confirmed for individual investors and 18 themes for institutional investors. The results also showed that project profitability, risk-taking, and political conditions were among the most important factors affecting the participation of individual investors, and that parallel market returns, inflation, project risk, and collateral were among the most important factors affecting the participation of institutional investors.

Conclusion/implications: This research can provide practical suggestions for managers of crowdfunding platforms to increase the likelihood of success of crowdfunding projects. Since the geographical factor does not affect investor participation in crowdfunding projects, platforms can finance projects from different parts of the country with the help of individual and institutional investors. In addition to the above, given that collateral factors, parallel market returns, project risk, and inflation are among the most important factors affecting the participation of institutional investors, and project profit factors, risk-taking, political conditions, parallel market returns, and inflation are the most effective factors affecting the participation of individual investors in crowdfunding projects, crowdfunding platform managers can consider these issues in their negotiations with legal and natural person for investment so that their negotiations lead to investor participation in crowdfunding projects. Negotiations between crowdfunding platforms and institutional investors should focus more on the type of collateral, parallel market returns, and comparing it with the project profit and project risks. In contrast, in negotiations with individuals investors, platform managers should focus more on the project profit, their risk-taking, and parallel market returns, so that they can determine the platform's success in successfully financing projects.

platform's success in successfully financing projects.