杰克股份：股票交易异常波动公告

Group 1 - The core point of the article is that Jack Co., Ltd. announced a significant stock price fluctuation, with a cumulative increase of 20% over three consecutive trading days from August 13 to August 15, 2025, indicating abnormal trading activity [1] - The company conducted a self-examination and confirmed with its controlling shareholder and actual controller that there are no undisclosed significant matters as of the date of the announcement [1]