Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 2 of 2
Full-Text Articles in Business
On The Efficiency Of Stock Markets: A Case Of Selected Opec Member Countries, Ebenezer A. Olubiyi, Peter O. Olopade
On The Efficiency Of Stock Markets: A Case Of Selected Opec Member Countries, Ebenezer A. Olubiyi, Peter O. Olopade
CBN Journal of Applied Statistics (JAS)
The study investigates the stock market efficiency of selected OPEC member countries within the context of random walk hypothesis and volatility approaches using monthly data on stock market indices from January, 2005 to April, 2016. Parametric (variance ratio: homoskedastic and heteroskedastic martingale), nonparametric (the Wright ranks and scores) tests and ARCHtype estimation are performed. Results of both parametric and nonparametric tests indicate that only Qatar’s stock market is weak-form efficient. The volatility results suggest that monthly stock returns of OPEC countries are volatile, with Qatar being most volatile and shocks to volatility of stock returns are asymmetric. The implications of …
Modeling Volatility Persistence And Asymmetry With Exogenous Breaks In The Nigerian Stock Returns, David A. Kuhe
Modeling Volatility Persistence And Asymmetry With Exogenous Breaks In The Nigerian Stock Returns, David A. Kuhe
CBN Journal of Applied Statistics (JAS)
This study examines the volatility persistence and asymmetry with exogenous breaks in Nigerian stock market. The study utilizes daily closing quotations of stock prices from the Nigerian stock exchange for the period 3rd July, 1999 to 12th June, 2017. Standard symmetric GARCH (1,1), asymmetric EGARCH (1,1) and GJR-GARCH (1,1) models with and without structural breaks were employed to measure shocks persistence and leverage effects in the presence of varying distributional assumptions. The empirical findings showed high persistence of shocks in the return series for the estimated models. However, the study found significant reduction in shocks persistence when structural breaks were …