Comparing symmetric and asymmetric volatility estimates for S&P index prices. Periodicals of Engineering and Natural Sciences, [S. l.], v. 7, n. 1, 2019. DOI: 10.21533/pen.v7.i1.1463. Disponível em: https://pen.ius.edu.ba/index.php/pen/article/view/1463. Acesso em: 15 jul. 2026.