Group 1 - On September 11, 28 Hong Kong-listed companies conducted share buybacks, totaling 16.42 million shares and an amount of 639 million HKD [1][2] - Tencent Holdings repurchased 874,000 shares for 550 million HKD, with a year-to-date total buyback amount of 50.50 billion HKD [1][2] - Hang Seng Bank repurchased 210,000 shares for 24.88 million HKD, with a year-to-date total buyback amount of 69.60 million HKD [1][2] - Stone Four Pharmaceutical Group repurchased 6 million shares for 18.14 million HKD, with a year-to-date total buyback amount of 8.42 million HKD [1][2] Group 2 - The highest buyback amount on September 11 was from Tencent Holdings at 550 million HKD, followed by Hang Seng Bank at 24.88 million HKD [1][2] - In terms of share quantity, Stone Four Pharmaceutical Group had the highest buyback volume with 6 million shares, followed by Yongda Automobile and Puhua Heshun with 1.5 million and 1.35 million shares respectively [1][2] - China Sanjiang Chemical's recent buyback was its first of the year, while Tencent Holdings has conducted multiple buybacks totaling 50.50 billion HKD this year [2]