CHEN, Shiyun. A Comparative Study of the Markowitz Model and the Single Index Model under Bull and Bear Market Scenarios. Journal of Innovation and Development, [S. l.], v. 14, n. 2, p. 471–480, 2026. DOI: 10.54097/6jhv5m82. Disponível em: https://drpress.org/ojs/index.php/jid/article/view/33015. Acesso em: 22 aug. 2026.