Open Access Open Access  Restricted Access Subscription or Fee Access

GARCH model for volatility in stock return series of Vietnam stock market

Duc Thang Le, Qiang Zhang

Abstract


This paper examines the features of the stock return volatility and the presence of structural breaks in return variance of VN-Index in the Vietnam stock market by using the iterated cumulative sums of squares (ICSS) algorithm. The relationship between Vietnam stock market’s volatility shifts and impacts of global crisis is also detected. Using a long-span data, the results show that daily stock returns can be characterized by GARCH and GARCH in mean (GARCH-M) models while threshold GARCH (T-GARCH) are not suitable. Further evidence also reveals that when sudden shifts are taken into account in the GARCH models, reduction in the volatility persistence is found. It suggests that many previous studies may have overestimated the degree of volatility persistence existing in financial time series. The small value of coefficients of the dummies representing breakpoints in modified GARCH model implies that the conditional variance of stock return is much affected by past trend of observed shocks and variance. Our results have important implications regarding advising investors on decisions concerning pricing equity, portfolio investment and management, hedging and forecasting. Moreover, it is also helpful for policy-makers in making and promulgating the financial policies.

Keywords


Volatility; Vietnam stock market; VN-Index; stock return, GARCH.

Full Text:

PDF


Disclaimer/Regarding indexing issue:

We have provided the online access of all issues and papers to the indexing agencies (as given on journal web site). It’s depend on indexing agencies when, how and what manner they can index or not. Hence, we like to inform that on the basis of earlier indexing, we can’t predict the today or future indexing policy of third party (i.e. indexing agencies) as they have right to discontinue any journal at any time without prior information to the journal. So, please neither sends any question nor expects any answer from us on the behalf of third party i.e. indexing agencies.Hence, we will not issue any certificate or letter for indexing issue. Our role is just to provide the online access to them. So we do properly this and one can visit indexing agencies website to get the authentic information. Also: DOI is paid service which provided by a third party. We never mentioned that we go for this for our any journal. However, journal have no objection if author go directly for this paid DOI service.