How Rebalancing Frequency Affects Portfolio Returns
Rebalancing resets your portfolio back to its target allocation after market movements cause drift. If stocks rise faster than bonds, your stock weighting grows above target, increasing risk. Rebalancing systematically sells the outperformer and buys the underperformer to restore balance.
In a deterministic model with fixed annual returns, rebalancing frequency has minimal impact. The real benefit appears in volatile markets through volatility harvesting — regular rebalancing buys low and sells high over time. However, frequent rebalancing incurs more transaction costs and potential tax events, which erode gains. Annual or threshold-based rebalancing (drift of 5%+) is generally optimal.
Frequently Asked Questions
Annual or threshold-based rebalancing (when allocation drifts more than 5%) balances discipline and cost. Monthly rebalancing is rarely worth the extra transaction costs.
When stocks return more than bonds with fixed rates, the unbalanced portfolio naturally tilts toward stocks, capturing more higher returns — at the cost of increased risk concentration.