Group 1 - The plastic sector experienced a slight increase of 0.19% on July 30, with Shangwei New Materials leading the gains [1] - The Shanghai Composite Index closed at 3615.72, up 0.17%, while the Shenzhen Component Index closed at 11203.03, down 0.77% [1] - Key stocks in the plastic sector showed significant price increases, with Shangwei New Materials rising by 9.37% to a closing price of 92.07 [1] Group 2 - The plastic sector saw a net outflow of 1.056 billion yuan from major funds, while retail investors contributed a net inflow of 999.3 million yuan [2] - Among the top gainers, Shangwei New Materials had a net inflow of 39.73 million yuan from major funds, while retail investors contributed a net inflow of 3.53 million yuan [3] - Conversely, Nanjing Zilong experienced a decline of 5.49%, closing at 32.85, with a trading volume of 133,400 shares [2]