并购重组概念活跃，ST板块连续大涨，一季度多家基金公司旗下产品重仓ST个股

Core Viewpoint - The recent introduction of new merger and acquisition regulations has led to increased interest and investment in ST stocks, particularly those with restructuring expectations, despite the need for cautious observation in the long term [1][2]. Group 1: Market Activity and Trends - The ST sector index has risen by 5.11% as of May 21, driven by expectations of restructuring [1]. - *ST赛隆 has seen a significant price increase of 60.23% from April 29 to May 22, reflecting heightened market speculation regarding its potential restructuring [2]. - The new merger and acquisition regulations have revitalized interest in ST stocks and micro-cap stocks, particularly after the disclosure of annual reports, which often reveal poor performance leading to valuation declines [2]. Group 2: Institutional Investment - In the first quarter, several public funds, including those from 易方达, 景顺长城, and 博时, have heavily invested in ST stocks, indicating a strategic focus on these assets [1][4]. - As of the end of last week, 21 public institutions participated in 31 A-share companies' private placements, with a total allocation of 9.785 billion yuan and a floating profit of 1.695 billion yuan, representing a floating profit ratio of 17.32% [3]. Group 3: Company-Specific Developments - Companies like *ST华通 and 东方通 have been highlighted for their significant presence in public fund portfolios, with 东方通 facing severe audit issues leading to risk warnings [4]. - *ST松发 has received approval for restructuring through major asset swaps, indicating ongoing interest from public funds despite the overall decline in interest in ST stocks due to stricter delisting regulations [5].