“…We adopt the approach of Chu, Stinchcombe, and White (1996) that sequentially monitors the stability of model parameters based on historical sample. For relevant literatures, see Berkes, Gombay, Horvárh, and Kokoszaka (2004), Chu et al (1996), Horváth, Hušková, Kokoszka, and Steinebach (2004), Hušková and Kirch (2012) and Na et al (2011), and the references therein.…”