What is portfolio rebalancing?
Just like your car needs a periodic service to stay in tune, here's why you should rebalance your portfolio from time to time.
A portfolio’s asset allocation reflects an investor’s goals and temperament—the need for return as well as the ability to withstand market turbulence.
Over time, market fluctuations can affect your asset allocation weightings and change the risk/return profile of your portfolio.
For example, say your target asset mix is a 50/50 split between shares and bonds. You originally invest $3,000 in a shares fund, which buys 20 units. You invest another $3,000 in a bond fund, which also buys 20 units. Your $6,000 portfolio balance is split evenly between stocks and bonds, matching your target.
Let’s say that over time your share fund units have consistently outperformed your bond fund units. For simplicity, let’s also say you don’t reinvest your dividends or capital gains or make any additional contributions, so you still own 20 units of each fund.
As a result of market fluctuations alone, your 20 share fund units are now valued at $5,000, and your 20 bond fund units are worth $2,000. Your total portfolio balance - $7,000 - is now split approximately 70/30 between shares and bonds, making your portfolio overweight in shares.
This scenario may be profitable right now—after all, you have more money invested in the higher-performing asset class. So what’s the danger?
What goes up can come down. If you lose parity with your target asset mix by remaining more heavily invested in shares and they go down in value, you can have more to lose than you anticipated.
Rebalancing from one asset class to another (in this case, selling share fund units and buying bond fund units) can put your portfolio back on track and make sure you’re not taking on more risk than you are comfortable with.
Why should investors rebalance?
Selling a well-performing asset and buying an investment with lower returns may seem counterintuitive, but the objective of rebalancing is to manage risk rather than maximise return.
When investors select an asset allocation, they choose a mix of assets that is expected to produce returns that can help them meet their goals with a level of risk they can tolerate.
By periodically rebalancing, investors can diminish the tendency for portfolios to drift to a risk level that is inconsistent with their risk profile.
Rebalancing can also help with discipline and emotional control when markets are volatile.
A set policy will trigger rebalancing events in a consistent manner no matter which direction markets head, which means investors are less likely to make any rash decisions to buy or sell securities that may jeopardise their long-term investment goals.