MSCI will release on May 12 the list of securities that will be added or deleted to the emerging market index, which is tracked by about $1.5 trillion in assets under management.
According to historical analysis using Kensho, the Hang Seng Enterprises index that tracks mainland firms listed in Hong Kong gained 3.68 percent in the 20 trading days ahead of inclusion of the Chinese stocks in the MSCI Emerging Market Index in 1996.
Shares of JD.com and Baidu rose more than 14 percent in the month before MSCI's November addition of the stocks to its emerging market index, according to Kensho, while Alibaba gained 0.2 percent.
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Performance of Chinese e-commerce firms sheds some light on China's progress in transitioning from a manufacturing-based economy to a consumer-based economy.
Recent data on the country's services sector has showed moderate growth. Overnight, the Caixin/Markit China services PMI showed a decline to 51.8 in April from 52.2 in March. The official non-manufacturing PMI reported over the weekend fell to 53.5 from 53.8.
Alibaba reported revenue of 24.2 billion yuan ($3.7 billion) for the quarter ended March 31, rising 39 percent from the year-ago period and topping expectations of 23.22 billion yuan. Gross merchandise volume (GMV), or the total value of goods transacted on the firm's platforms on China retail marketplaces, rose 24 percent to 742 billion yuan.
Noted short-seller Jim Chanos told CNBC Wednesday he is still betting against Alibaba given his concerns about financial metrics and cash flow for the firm.
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Baidu was more than 1 percent lower in afternoon trade. Shares fell nearly 8 percent Monday after news Chinese authorities would investigate the internet firm over the death of a university student who used the search engine to find a cancer treatment.
Disclosure: CNBC's parent NBCUniversal is a minority investor in Kensho.