Optimizing Rebalancing Strategy for Low Transaction Costs

John is a portfolio manager for a large investment fund. He frequently makes adjustments to his clients' portfolios based on market conditions, investment opportunities, and client goals. Recently, he has been analyzing the impact of transaction costs, which include brokerage fees, market impact, and bid-ask spreads, on his trading decisions. John is particularly interested in how different trading strategies can influence these costs.

After reviewing various trading models, John notes that certain strategies may lead to higher transaction costs due to market liquidity and volatility. He is considering a rebalancing approach that minimizes these costs while still achieving the desired allocation across various asset classes.

Which of the following rebalancing strategies is likely to incur the lowest transaction costs over time?