收评：主要股指小幅下跌 PEEK材料板块和可控核聚变板块领涨

Market Overview - The major stock indices in Shanghai and Shenzhen opened lower on May 16, with the Shanghai Composite Index experiencing a decline after initial fluctuations, while the Shenzhen Component and ChiNext indices showed wider fluctuations after filling gaps [1] - The Shanghai Composite Index closed at 3367.46 points, down 0.40%, with a trading volume of approximately 435.6 billion yuan; the Shenzhen Component closed at 10179.60 points, down 0.07%, with a trading volume of about 653.9 billion yuan; the ChiNext Index closed at 2039.45 points, down 0.19%, with a trading volume of around 298.5 billion yuan [1] Sector Performance - The PEEK materials sector and controllable nuclear fusion sector saw significant gains in the morning session, although the gains narrowed during the day, remaining among the top performers [1] - Other sectors that experienced notable increases included COVID-19 drug concepts, automotive parts, integrated die-casting, and cultivated diamonds, while sectors such as chemical fibers, warehousing logistics, and seed industry faced larger declines [1] Institutional Insights - According to Jifeng Investment Advisory, the A-share market is gradually finding a bottom with medium to long-term investment opportunities, driven by a series of counter-cyclical adjustment policies [2] - Guoyuan Securities noted that the "618" shopping festival has seen a shift in pre-sale periods, with platforms like Tmall and JD.com simplifying mechanisms and increasing subsidies, leading to strong performances from domestic products [2] - Guojin Securities highlighted that financial technology companies are actively seeking growth points in areas such as AI and overseas expansion, with a positive outlook for C-end stock trading software companies as market activity remains robust [2] Policy Developments - The Ministry of Commerce held a meeting on May 15 to promote the optimization of the departure tax refund policy, emphasizing its role in boosting consumption and responding to external shocks [3] - The State-owned Assets Supervision and Administration Commission (SASAC) announced a meeting to discuss further deepening the reform of state-owned enterprises, focusing on high-quality completion of reform actions by 2025 [4]