Core Viewpoint - The article emphasizes the importance of two core principles in investment: the Certainty Principle and Cost-Performance Thinking, which help investors make informed decisions in a volatile market environment [2][3]. Group 1: Certainty Principle - The Certainty Principle suggests that investors should filter out noise and focus on high-probability decisions, as many apparent opportunities have low success rates [4][5]. - An example is given using World Cup betting, where betting on popular teams may seem attractive but often has a low probability of success, making it a poor investment choice [6][7][8]. - Investors should avoid making decisions based on short-term market fluctuations or technical indicators, as these often do not provide clear directional guidance [10][12]. - Historical data shows that significant inflows of capital, such as northbound funds exceeding 20 billion, are rare and do not consistently indicate market trends, thus should not be the basis for investment decisions [13]. Group 2: Cost-Performance Thinking - Cost-Performance Thinking involves balancing risk and return, rather than striving for perfect timing in buying and selling [14][15]. - Investors should recognize when the market is overvalued and consider selling rather than waiting for the absolute peak, as this is often unrealistic [18][19]. - The article highlights that during periods of high valuation, such as the Shanghai Composite Index reaching over 5000 points, investors should gradually reduce their positions to secure profits [20][22]. - In contrast, during market downturns, such as the Shanghai Composite Index dropping to 3300 points, investors should consider buying if the risk is manageable and the potential return is significant [25][26]. - The essence of investment is viewed as a probability game, where understanding the balance of risk and reward is crucial for making sound investment decisions [27][28].