午间涨跌停股分析：73只涨停股、5只跌停股，CPO概念走强，剑桥科技涨停

Group 1 - A-shares saw 73 stocks hitting the daily limit up and 5 stocks hitting the limit down during the first half of the trading day on October 20 [1] - The forestry sector was active, with Pingtan Development achieving two consecutive limit ups [1] - The CPO concept strengthened, with Cambridge Technology hitting the limit up [1] - The coal mining sector rose, with Dayou Energy achieving 6 limit ups in 7 days, Antai Group achieving 3 consecutive limit ups, and Yunmei Energy hitting the limit up [1] Group 2 - *ST Yuancheng experienced 6 consecutive limit downs [2] - *ST Yazhen faced 2 consecutive limit downs [2] - *ST Zhengping and Hunan Baiyin also hit the limit down [2]