Group 1 - The core point of the article is that Saiyi Information announced the pledge of shares by its controlling shareholder Zhang Chengkang, which will be extended until January 26, 2027 [1] - Zhang Chengkang pledged 4,500,000 shares, representing 10.74% of his total holdings and 1.10% of the company's total share capital [1] - The pledge is secured by Guotai Junan Securities Co., Ltd. as the pledgee [1]