Cosmos Machinery Enterprises added to this week's already impressive gains with a 64.5 per cent leap yesterday. The plastics machinery maker surged $1.245 to close at $3.175 on trade of 64.47 million shares. The rise takes its gains since last Friday to 142 per cent. Investors have pushed the stock sharply higher since China Resources (Holdings) announced that it had bought a 24 per cent stake in the company at the weekend. China Resources, the commercial arm of China's Ministry of Foreign Trade and Economic Co-operation, said the deal marked the start of closer relationship between the firms.