Key points
- CXMT passes China's biggest banks in Shanghai
- What Korean STAR Market ETFs need before buying CXMT
- CXMT is still missing from Stock Connect
- CXMT's next chance at the STAR 50
CXMT (창신메모리, 688825), China's biggest DRAM maker, now carries the largest weight in the Shanghai Composite, three months after it listed. Most Korean funds that invest in Shanghai's tech board still can't buy it.
CXMT's weight in the index was 4.67% as of October 27, ahead of Agricultural Bank of China at 3.83% and ICBC at 3.77%, according to China Securities Index data reported by Hankyung TV (한국경제TV). It also joined the STAR Market Composite, the broad index for Shanghai's tech board, with a 15.74% weight. Cambricon Technologies is second there at 5.05%.
CXMT shares rose 3.16% on October 28 to close at 44.36 yuan ($6.67).
CXMT qualified early because of its size
The Shanghai Composite usually adds a new stock one year after it lists. A stock whose average daily market value since listing ranks in the top 10 on the Shanghai market gets in after three months instead. CXMT listed on July 27, so it reached the three-month mark on October 27.
Kim Seong-eun (김성은), a researcher at Hana Securities (하나증권), estimated 17.1 billion to 20.8 billion yuan ($2.6 billion to $3.1 billion) could flow into CXMT in the fourth quarter from its addition to the Shanghai Composite, the STAR Market Composite, and a STAR Market chip index, Junggi Economy (중기이코노미) reported. Hana said that equals only 25% to 30% of the value of shares allotted to institutions in the IPO, which start to unlock in late January 2027. Those shares were worth about 68.5 billion yuan ($10.3 billion) at the October 16 close.
Most Korean STAR Market ETFs follow an index CXMT isn't in
Foreign investors' direct access to Shanghai's STAR Market is limited. Most Korean "China STAR Market" products are passive ETFs that track the STAR 50 index, so they would need CXMT to join that index before buying it, Seoul Economic Daily (서울경제) reported in July. CXMT isn't among the 50 stocks on China Securities Index's STAR 50 constituent list dated October 28.
The Korean ETFs buy Chinese shares through Stock Connect, the link that lets foreign investors trade Shanghai stocks from Hong Kong. They also need CXMT to be named an eligible stock there. CXMT isn't on Hong Kong Exchanges' list of eligible Shanghai stocks updated October 28. Three other STAR Market chip companies, Cambricon, Hygon Information Technology, and SMIC, are on it.
Some Korean mutual funds could buy CXMT right after it listed, the same July report said. They hold QFII licenses, which let foreign institutions invest in mainland Chinese shares directly. The report names funds run by Korea Investment Trust Management (한국투자신탁운용), KB Asset Management (KB자산운용), Samsung Asset Management, and Shinhan Asset Management. Whether they buy is each manager's decision. These funds don't publish their holdings every day, so investors may not learn about a change for at least 10 business days.
The STAR 50 review is due in late November
The STAR 50 lets one of the five largest STAR Market stocks join three months after listing, ahead of the normal schedule. CXMT reached the three-month mark on October 27 and is the largest stock in the STAR Market Composite. Results of the next STAR 50 review are due in late November, and changes take effect December 14. The index provider hasn't announced whether CXMT will be added.
ETFs that track the STAR 50 hold more than 170 billion yuan ($25.5 billion) in mainland China, and about 180 billion yuan ($27.0 billion) when products sold outside China are included.
Earlier this month, Samsung and SK Hynix fell after CXMT said it plans to sell server memory built on a smaller 4F² cell design by the end of the year, and Samsung's chip technology chief later confirmed Samsung is developing the same design. CXMT has also hired engineers from Korea. At least 27 Samsung and SK Hynix veterans have worked there.
Dollar figures use 6.6547 yuan per dollar, the Yahoo Finance rate on October 28, 2026.
