“…In addition, this study accomplishes that using small data of symmetric volatility information is better than using big data sample, this result indicates that small data of symmetric volatility information is full of high-quality information for better prediction accuracy, therefore, this result is consistent with Yudelson et al (2014) and Faraway and Augustin (2018) when they demonstrated that small data outperforms big data in prediction accuracy when small data generate superior inferences than the low-quality large sample. In conclusion, this paper supports the findings of Das et al (2017), Wibowo et al (2017), Alkhoshi and Belkasim (2018), Livieris et al (2019), Aslam et al (2020), Peng and Tang (2020), Wang et al (2020), Irsalinda et al (2020), Yu and Yan (2020), Gandhmal and Kumar (2020), and Peng and Tang (2020), in which modern techniques like machine learning, artificial intelligence and DL are effective tools in the capital markets by affording advanced knowledge to the financial investors for the well-organized managing of portfolios, to reduce trading risk and to make right financial decisions, which leads to the inevitability of using new technological techniques in Islamic capital markets due to the effectiveness of those modern techniques in the predicting process than other classical statistical tools which remained paralyzed to evaluate big data time series, this inevitability of updating the classical statistical tools obliges the financial investors and decision-makers to employ new techniques which only machine learning, artificial intelligence and DL can offer.…”