Indonesia’s stock market has seen an increase in investment due to the ease of investing and the availability of information about stocks on different social media platforms. This research uses a social network approach to analyze overconfidence behavior in millennial stock investors. This research uses a descriptive quantitative method. The population used in this study are capital market investors in the Greater Solo area who are millennials (<30 years). The number of stock investors in the Greater Solo area is 60,542 investors. The sampling technique in this study was non-probability sampling using purposive sampling. This research uses the AMOS SEM (Structural Equation Model) analysis tool. The conclusion of this study is that millennial investors’ overconfidence behavior increases influenced by financial literacy. investor skills. family ties and friendship ties. The contribution of this research can be applied to understand and educate millennial investors in order to overcome overconfidence behavior so that they can anticipate the losses received. This research may have implications for improving Behavioral Finance Integration Incorporating insights from behavioral finance into investment strategies can help mitigate the negative effects of overconfidence. The limitation in this study is that the scope used in the study is only in the greater solo area.

Aljifri, R. (2023). Investor psychology in the stock market: An empirical study of the impact of overconfidence on firm valuation. Borsa Istanbul Review, 23(1), 93–112. https://doi.org/10.1016/j.bir.2022.09.010

Aljughaiman, A. A., & Chebbi, K. E. (2022). Do Investor Overconfidence and Loss Aversion Drive Saudi Firm Market Performance? The Moderating Effect of Corporate Governance. Sustainability, 14(16), 10072. https://doi.org/10.3390/su141610072

Almansour, B. Y., Elkrghli, S., & Almansour, A. Y. (2023). Unravelling the Complexities of Cryptocurrency Investment Decisions: A Behavioral Finance Perspective from Gulf Investors. International Journal of Professional Business Review, 8(7), e03265. https://doi.org/10.26668/businessreview/2023.v8i7.3265

Ameliawati, M., & Setiyani, R. (2018). The Influence of Financial Attitude, Financial Socialization, and Financial Experience to Financial Management Behavior with Financial Literacy as the Mediation Variable. KnE Social Sciences, 3(10), 811. https://doi.org/10.18502/kss.v3i10.3174

Balletto, G., Ladu, M., Milesi, A., et al. (2022). Walkable City and Military Enclaves: Analysis and Decision-Making Approach to Support the Proximity Connection in Urban Regeneration. Sustainability, 14(1), 457. https://doi.org/10.3390/su14010457

Banstola, R. S., Ogino, T., & Inoue, S. (2020). Self-esteem, perceived social support, social capital, and risk-behavior among urban high school adolescents in Nepal. SSM - Population Health, 11, 100570. https://doi.org/10.1016/j.ssmph.2020.100570

Candiya Bongomin, G. O., Munene, J. C., Ntayi, J. M., et al. (2017). Financial literacy in emerging economies. Managerial Finance, 43(12), 1310–1331. https://doi.org/10.1108/mf-04-2017-0117

Bongomin, G. O. C., Munene, J. C., Ntayi, J. M., et al. (2018). Nexus between financial literacy and financial inclusion. International Journal of Bank Marketing, 36(7), 1190–1212. https://doi.org/10.1108/ijbm-08-2017-0175

Brailovskaia, J., Ozimek, P., Rohmann, E., et al. (2023). Vulnerable narcissism, fear of missing out (FoMO) and addictive social media use: A gender comparison from Germany. Computers in Human Behavior, 144, 107725. https://doi.org/10.1016/j.chb.2023.107725

Brunzel, J. (2021). Overconfidence and narcissism among the upper echelons: a systematic literature review. Management Review Quarterly, 71(3), 585–623. https://doi.org/10.1007/s11301-020-00194-6

Chaudary, S., Zafar, S., & Tang, T. L.-P. (2022). Investors’ financial aspirations excite investment decisions: current income, future inheritance expectations, and short-term and long-term decisions—The Matthew Effect in Pakistan’s emerging markets. International Journal of Emerging Markets, 19(5), 1306–1334. https://doi.org/10.1108/ijoem-07-2021-1098

Chen, M., Zheng, Q. P., Boginski, V., et al. (2021). Influence maximization in social media networks concerning dynamic user behaviors via reinforcement learning. Computational Social Networks, 8(1). https://doi.org/10.1186/s40649-021-00090-3

Cheng, C. C., & Shiu, E. C. (2019). How to enhance SMEs customer involvement using social media: The role of Social CRM. International Small Business Journal: Researching Entrepreneurship, 37(1), 22–42. https://doi.org/10.1177/0266242618774831

Danila, N., Noreen, U., Azizan, N. A., et al. (2020). Growth Opportunities, Capital Structure and Dividend Policy in Emerging Market: Indonesia Case Study. The Journal of Asian Finance, Economics and Business, 7(10), 1–8. https://doi.org/10.13106/jafeb.2020.vol7.no10.001

De Los Santos-Gutiérrez, A., Molchanova, V. S., González-Fernandez, R., & García-Santillán, A. (2022). Financial Literacy, Savings Culture and Millennials Students Behavior Towards Retirement. European Journal of Contemporary Education, 11(2), 491–503. https://doi.org/10.13187/ejced.2022.2.491

Devie, D., Liman, L. P., Tarigan, J., et al. (2020). Corporate social responsibility, financial performance and risk in Indonesian natural resources industry. Social Responsibility Journal, 16(1), 73–90. https://doi.org/10.1108/srj-06-2018-0155

El-Ansary, O., & Ahmed, A. M. (2023). Does overconfidence blur out the investment efficiency? The managerial overconfidence and internal financing effect on investment efficiency: evidence from MENA region. International Journal of Emerging Markets. https://doi.org/10.1108/ijoem-06-2021-0931

EL-Ansary, O., & Ahmed, A. M. (2023). The moderating role of CEO overconfidence on debt maturity decisions: evidence from the MENA region. Journal of Financial Reporting and Accounting. https://doi.org/10.1108/jfra-03-2023-0121

Endri, E., Sari, A. K., Budiasih, Y., et al. (2020). Determinants of Profit Growth in Food and Beverage Companies in Indonesia. Journal of Asian Finance, Economics and Business, 7(12), 739–748. https://doi.org/10.13106/JAFEB.2020.VOL7.NO12.739

Frihartina, S. R., & Nurjannah, D. (2021). Response of LQ45 Stock Market on Indonesia Legislative and Presidential Election Result in 2019. Jamanika (Jurnal Manajemen Bisnis Dan Kewirausahaan), 1(1), 30–36. https://doi.org/10.22219/jamanika.v1i1.16019

Gali, N., Niemand, T., Shaw, E., et al. (2020). Social entrepreneurship orientation and company success: The mediating role of social performance. Technological Forecasting and Social Change, 160, 120230. https://doi.org/10.1016/j.techfore.2020.120230

Gherghina, Ștefan C., Botezatu, M. A., Hosszu, A., et al. (2020). Small and Medium-Sized Enterprises (SMEs): The Engine of Economic Growth through Investments and Innovation. Sustainability, 12(1), 347. https://doi.org/10.3390/su12010347

Grohmann, A., Klühs, T., & Menkhoff, L. (2018). Does financial literacy improve financial inclusion? Cross country evidence. World Development, 111, 84–96. https://doi.org/10.1016/j.worlddev.2018.06.020

Gupta, S., & Shrivastava, M. (2021). Herding and loss aversion in stock markets: mediating role of fear of missing out (FOMO) in retail investors. International Journal of Emerging Markets, 17(7), 1720–1737. https://doi.org/10.1108/ijoem-08-2020-0933

Hermuningsih, S., Prima Sari, P., & Rahmawati, A. D. (2021). Abnormal returns on indonesia stock exchange during COVID-19 pandemic. JABE (Journal of Applied Business and Economic), 7(3), 367. https://doi.org/10.30998/jabe.v7i3.8198

Hikmah, R., Djuwita, D., & Widagdo, R. (2019). Effect of Financial Literation and Financing-Effectivity toward the Growth of Small Enterprises: Case Study in Bank Syariah Mandiri, Majalengka. AL-FALAH: Journal of Islamic Economics, 4(2), 163. https://doi.org/10.29240/alfalah.v4i2.941

In, C., Kim, T., & Park, S. (2020). Key Audit Matters for Production-To-Order Industry and Conservatism. International Journal of Financial Studies, 8(1), 5. https://doi.org/10.3390/ijfs8010005

Inghelbrecht, K., & Tedde, M. (2024). Overconfidence, financial literacy and excessive trading. Journal of Economic Behavior & Organization, 219, 152–195. https://doi.org/10.1016/j.jebo.2024.01.010

Lee, Y., & Na, S. (2023). Fear of Missing Out: An Antecedent of Online Fan Engagement of Sport Teams’ Social Media. Communication & Sport, 216747952311745. https://doi.org/10.1177/21674795231174565

Lei, S. (2019). Financial advice and individual investors’ investment decisions. Applied Economics Letters, 26(13), 1129–1132. https://doi.org/10.1080/13504851.2018.1540832

Lei, S., & Ramos Salazar, L. (2022). Use of social networks in stock investment. International Journal of Bank Marketing, 40(1), 110–127. https://doi.org/10.1108/IJBM-04-2021-0158

Lei, X., Wu, H., & Ye, Q. (2022). Pregnant women’s coping strategies, participation roles and social support in the online community during the COVID-19. Information Processing and Management, 59(3). https://doi.org/10.1016/j.ipm.2022.102932

Li, L., Li, Y., Wang, X., Xiao, T., & Zhu, H. (2022). Hedge fund networks, information dissemination, and stock price comovement: Evidence from China. International Review of Financial Analysis, 83. https://doi.org/10.1016/j.irfa.2022.102224

Llopis-Amorós, M.-P., Gil-Saura, I., Ruiz-Molina, M. E., et al. (2019). Social media communications and festival brand equity: Millennials vs Centennials. Journal of Hospitality and Tourism Management, 40, 134–144. https://doi.org/10.1016/j.jhtm.2019.08.002

Mindra, R., & Moya, M. (2017). Financial self-efficacy: a mediator in advancing financial inclusion. Equality, Diversity and Inclusion: An International Journal, 36(2), 128–149. https://doi.org/10.1108/edi-05-2016-0040

Morgan, P. J., & Long, T. Q. (2020). Financial literacy, financial inclusion, and savings behavior in Laos. Journal of Asian Economics, 68, 101197. https://doi.org/10.1016/j.asieco.2020.101197

Nadeem, M. A., Qamar, M. A. J., Nazir, M. S., Ahmad, I., Timoshin, A., & Shehzad, K. (2020). How Investors Attitudes Shape Stock Market Participation in the Presence of Financial Self-Efficacy. Frontiers in Psychology, 11. https://doi.org/10.3389/fpsyg.2020.553351

Nguyen, B. (2022). Small business investment: The importance of financing strategies and social networks. International Journal of Finance & Economics, 27(3), 2849–2872. Portico. https://doi.org/10.1002/ijfe.2302

Nivedhitha, K. S., & Sheik Manzoor, A. K. (2020). Get employees talking through enterprise social media! Reduce cyberslacking: a moderated mediation model. Internet Research, 30(4), 1167–1202. https://doi.org/10.1108/intr-04-2019-0138

Parveen, S., Satti, Z. W., Subhan, Q. A., et al. (2020). Exploring market overreaction, investors’ sentiments and investment decisions in an emerging stock market. Borsa Istanbul Review, 20(3), 224–235. https://doi.org/10.1016/j.bir.2020.02.002

Patil, S., & Bagodi, V. (2021). A study of factors affecting investment decisions in India: The KANO way. Asia Pacific Management Review, 26(4), 197–214. https://doi.org/10.1016/j.apmrv.2021.02.004

Prihandini, W. (2020). Analyst Coverage and Corporate Tax Aggressiveness in Indonesia Stock Exchange. Binus Business Review, 11(1), 59–69. https://doi.org/10.21512/bbr.v11i1.5996

Rahman, M. M., Vu, X.-B. & Nghiem, S. (2022). Economic Growth in Six ASEAN Countries: Are Energy, Human Capital and Financial Development Playing Major Roles? Sustainability, 14(8), 4540. https://doi.org/10.3390/su14084540

Rashid, K., Tariq, Y. B., & Rehman, M. U. (2022). Behavioural errors and stock market investment decisions: recent evidence from Pakistan. Asian Journal of Accounting Research, 7(2), 129–145. https://doi.org/10.1108/ajar-07-2020-0065

Rossi-Goldthorpe, R. A., Leong, Y. C., Leptourgos, P., et al. (2021). Paranoia, self-deception and overconfidence. PLOS Computational Biology, 17(10), e1009453. https://doi.org/10.1371/journal.pcbi.1009453

Septyanto, D., Sayidah, N., & Assagaf, A. (2021). The Intention of Investors in Making Investment Decisions in Sharia Stocks: Empirical Study in Indonesian. Academic Journal of Interdisciplinary Studies, 10(4), 141. https://doi.org/10.36941/ajis-2021-0105

Shrotryia, V. K., & Kalra, H. (2023). COVID-19 and overconfidence bias: the case of developed, emerging and frontier markets. International Journal of Emerging Markets, 18(3), 633–665. https://doi.org/10.1108/ijoem-09-2020-1019

So, M. (2022). Analysis of the influence of enterprise managers’ overconfidence on the overinvestment behavior of listed companies under the media reports. Frontiers in Psychology, 13. https://doi.org/10.3389/fpsyg.2022.1018189

Ungeheuer, M., & Weber, M. (2021). The Perception of Dependence, Investment Decisions, and Stock Prices. The Journal of Finance, 76(2), 797–844. https://doi.org/10.1111/jofi.12993

Xu, H., Liu, Y., Song, B., et al. (2024). Local social network structure and promotion effectiveness in social commerce. Information Technology & People. https://doi.org/10.1108/itp-10-2021-0737

Yang, A. S. (2020). Investors’ trust and financial participation: Latent difficulty measurement. Asia Pacific Management Review, 25(2), 87–98. https://doi.org/10.1016/j.apmrv.2019.10.001

Yao, Q., Li, R. Y. M., Song, L., & Crabbe, M. J. C. (2021). Safety knowledge sharing on Twitter: A social network analysis. Safety Science, 143. https://doi.org/10.1016/j.ssci.2021.105411

Yeh, T.-M., & Ling, Y. (2022). Confidence in Financial Literacy, Stock Market Participation, and Retirement Planning. Journal of Family and Economic Issues, 43(1), 169–186. https://doi.org/10.1007/s10834-021-09769-1