每日钉一下（投资领域的免费午餐：再平衡策略）

Group 1 - The article discusses the importance of index fund investment and offers a free course on investment techniques for index funds [2] - It highlights the concept of rebalancing as a strategy to reduce volatility risk and maintain asset allocation [6][7] - The article outlines four common rebalancing strategies: periodic rebalancing, deviation-based rebalancing, valuation-based rebalancing, and volatility risk-based rebalancing [8][9][10][12][13] Group 2 - Periodic rebalancing involves resetting asset allocation at regular intervals, such as annually [9] - Deviation-based rebalancing triggers a rebalance when asset allocation deviates from the target by a certain percentage [10][11] - Valuation-based rebalancing focuses on adjusting allocations based on the relative valuations of assets rather than their prices [12] - Volatility risk-based rebalancing allocates assets according to their respective volatility levels [13]