2. According to the principle of combining sample stability with dynamic tracking, the Shanghai and Shenzhen 300 Index adjusts its constituent stocks every six months, and the proportion of each adjustment generally does not exceed 10%. Sample adjustment sets the buffer, and the new samples ranked within 240 will enter first, and the old samples ranked before 360 will be reserved first. When a sample stock company withdraws from the market, it will be removed from the index sample from the delisting date and replaced by the stock with the highest ranking among the candidate samples in the latest periodic adjustment of the index.