At first blush, stock trading this week is hardly a paragon of the market-efficiency theory, an oft-romanticized idea in ...

Research by Valentin Haddad, associate professor of finance at UCLA Anderson School of Management and his colleagues in 2022 is one such analysis. It concluded that the rise of passive investing ...

“This efficient markets view is a little bit of what I would call magical thinking,” said co-author Valentin Haddad, an associate finance professor at UCLA. “If a fraction of investors ...