Group 1 - On December 15, the Shanghai Composite Index fell by 0.55%, with institutional investors appearing on the trading lists of 33 stocks, net buying 16 and net selling 17 [1] - Institutional special seats had a total net purchase of 23.26 million yuan, marking the third consecutive day of net buying [1] - The stocks with the highest net purchases included LeiKe Defense, which closed at the daily limit with a turnover rate of 44.55% and a transaction amount of 5.475 billion yuan [2] Group 2 - LeiKe Defense saw a net purchase of 151.49 million yuan from institutional investors, with a total net inflow of 1.48 billion yuan throughout the day [2] - Zhongzhou Special Materials experienced a decline of 4.92% with a turnover rate of 31.05%, resulting in a net sale of 122.64 million yuan by institutions [2] - Xinghuan Technology rose by 17.27% with a turnover rate of 20.22%, leading to a net purchase of 55.23 million yuan by institutions [3] Group 3 - Among the stocks with the highest net sales, China Uranium Industry had a net sale of 114.78 million yuan, with a turnover rate of 53.41% [4] - Boying Special Welding had a net sale of 79.82 million yuan, with a turnover rate of 33.92% [4] - Anfu Technology saw a net sale of 76.49 million yuan, with a total net outflow of 90.29 million yuan [4] Group 4 - The average increase for stocks with institutional net purchases was 8.43%, outperforming the Shanghai Composite Index [3] - The stocks with significant performance included Keqiang Co. and Aisen Co., both closing at the daily limit [3] - A backtest of stocks with institutional net purchases over the past month showed a 47.66% probability of rising the next day [3] Group 5 - On December 15, 23 stocks appeared on the trading lists with the participation of the Shenzhen-Hong Kong Stock Connect, with net purchases including LeiKe Defense and Anfu Technology [7] - The net purchase amount for LeiKe Defense was 199.94 million yuan, while Anfu Technology had a net purchase of 75.13 million yuan [8] - Stocks with net sales included Enjie Co. and Bona Film Group, with net sales of 218.01 million yuan and 77.20 million yuan respectively [8]