Electronic signs displaying the Hang Seng Index is seen at the Exchange Square in Hong Kong on March 12, 2020. (ANTHONY KWAN / GETTY IMAGES)

Alibaba Group Holding Ltd will be included in Hong Kong’s Hang Seng in one of the biggest revamps in the benchmark index’s 50-year history.

Xiaomi Corp will also be joining the index, as will Wuxi Biologics Cayman Inc, according to Hang Seng Indexes Co on Friday as it unveiled the first major changes since the compiler began allowing dual-class shares and secondary listings

Xiaomi Corp will also be joining the index, as will Wuxi Biologics Cayman Inc, according to Hang Seng Indexes Co on Friday as it unveiled the first major changes since the compiler began allowing dual-class shares and secondary listings.

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The move could affect tens of billions of dollars in pension fund assets and exchange-traded funds that track the index. Sino Land Co, Want Want China Holdings Ltd and China Shenhua Energy Co were forced out of the 50-member gauge.

The changes will be effective Sept 7.

The Hang Seng Index is down 11 percent for the year, compared with the 15 percent gain for the Chinese mainland’s CSI 300 Index and the Nasdaq Composite’s 23 percent rise.

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“The inevitable trend is for Hong Kong’s equity benchmark to lose more local features and represent more of the Chinese economy,” according to Jackson Wong, asset management director at Amber Hill Capital Ltd, who spoke before the announcement. “Adding these companies will help it better reflect changes in the city’s equity market.”

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As of Friday’s trading close, at least 26 firms out the 50 Hang Seng members generate the majority of their revenue from the mainland.

More listings of mainland firms are in the pipeline, such as by Alibaba founder Jack Ma’s Ant Group, after debuts by NetEase Inc and JD.com Inc.