Hang Seng Index has fell 1.03%, with a year-to-date fell 1%; Hang Seng TECH Index has fell 2.15%, with a year-to-date fell 13.5%.SERES(09927) rose 5.09%, with a trading turnover 218.1 Million HKD, and a year-to-date fell 33.9%.
OMNIVISION(00501) rose 5%, with a trading turnover 239.8 Million HKD, and a year-to-date fell 9.7%.
BIREN TECH(06082) fell 7.69%, with a trading turnover 339.2 Million HKD, and a year-to-date rose 138.8%.
YOFC(06869) fell 6.84%, with a trading turnover 3.4 Billion HKD, and a year-to-date rose 316.2%.<img src="https://pub.pbkrs.com/screenshot/hk_company_top_five_2026-05-21_en-1779352231035159814.png?x-oss-process=style/lg" original-src="https://pub.pbkrs.com/screenshot/hk_company_top_five_2026-05-21_en-1779352231035159814.png"/>

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SERES(09927) rose 5.09%, with a trading turnover 218.1 Million HKD, and a year-to-date fell 33.9%. OMNIVISION(00501) rose 5%, with a trading turnover 239.8 Million HKD, and a year-to-date fell 9.7%. BIREN TECH(06082) fell 7.69%, with a trading turnover 339.2 Million HKD, and a year-to-date rose 138.8%. YOFC(06869) fell 6.84%, with a trading turnover 3.4 Billion HKD, and a year-to-date rose 316.2%.

- The Hang Seng Index fell by 1.03%, with a year-to-date decline of 1%.  
- The Hang Seng Tech Index decreased by 2.15%, accumulating a 13.5% loss for the year.  
- Notable movements include Sai Liu Si rising by 5.09% despite a 33.9% year-to-date drop, while Wall Group and Biran Technology saw gains and losses, respectively, throughout the year.

Top 5 HK Stock Gainers/Losers (>100B) (5.21)