This paper examines the efficiency of DJIM conventional and Islamic sectoral stock markets before and during the Covid-19 period. The study uses both sectoral stock markets' daily data from January 1, 2010, to August 1, 2022, and relies on the multifractal detrended fluctuation analysis (MF-DFA). Firstly, we find that the conventional and Islamic sectoral stock markets are multifractal in the short and long run. Secondly, conventional and Islamic sectoral stock markets are characterized by long-term memory features in small fluctuations. Thirdly, in terms of efficiency before the Covid-19 period, in the Islamic sectoral market, the healthcare sector is the most efficient in the short run, and the financial sector is the most efficient in the long run. During the Covid-19 period, in the conventional sectoral market, the financial sector was the most efficient in the short run, and the utility sector was the most efficient in the long run.

中文翻译：

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COVID-19 大流行期间伊斯兰和传统金融市场效率的多重分形去趋势波动分析

本文研究了 DJIM 传统和伊斯兰部门股票市场在 Covid-19 之前和期间的效率。该研究使用了2010年1月1日至2022年8月1日期间两个板块股票市场的每日数据，并依赖于多重分形去趋势波动分析（MF-DFA）。首先，我们发现传统和伊斯兰部门股票市场在短期和长期内都是多重分形的。其次，传统和伊斯兰行业股票市场具有小幅波动的长期记忆特征。第三，就Covid-19时期之前的效率而言，在伊斯兰部门市场中，医疗保健部门是短期效率最高的，而金融部门是长期效率最高的。在Covid-19期间，在传统部门市场中，金融部门是短期效率最高的，而公用事业部门是长期效率最高的。