What it means
When you invest money, you typically divide it among different types of assets based on your goals and comfort with risk, such as safer bonds and riskier shares. Over time, certain investments will grow faster than others.
If shares perform exceptionally well, they will make up a much larger portion of your portfolio than you originally intended, unintentionally exposing you to higher risk than you planned to take. Rebalancing means stepping in to fix this imbalance.
You sell some of the investments that have grown significantly and use the cash to buy more of the assets that have lagged behind. This disciplined approach forces you to automatically follow the golden rule of investing: sell high and buy low.
For non-finance managers and business leaders, this concept applies directly to managing corporate treasuries or personal wealth. Without regular check-ins, a portfolio becomes heavily concentrated in whatever asset happened to perform best recently.
Rebalancing brings everything back to a safe, intentional baseline. Most people rebalance their portfolios on a calendar schedule, such as every six months or once a year, or when an asset class drifts by a specific threshold, like five percentage points from the target.
It is a vital maintenance routine to ensure your money works hard without taking on accidental risks. Think of it like a rowboat.
If everyone on board crowds to one side because they see something shiny, the boat tilts dangerously. Rebalancing is simply moving people back to their proper seats to keep the boat level and safe.
In practice
Real-world examples
Example 1
An entrepreneur with a target of 60% shares and 40% cash holds $200,000. Shares grow until they represent 80% of the total, or $160,000, against a target of $120,000. The entrepreneur sells $40,000 of shares and moves it to cash to restore the 60/40 split.
Example 2
A growing SME keeps a $400,000 investment reserve split equally between government bonds and corporate equities. After a market boom, equities are worth $280,000 and bonds $120,000. The finance team sells $80,000 of equities and buys bonds, returning each side to $200,000.
Example 3
A tech startup founder has a personal retirement portfolio initially split between property funds and global shares. Each January the founder compares the two and trades back to the original split. This stops either asset class from quietly dominating their net worth and keeps the risk level in line with their plans.
Think of it
Think of it like a rowboat. If everyone on board crowds to one side because they see something shiny, the boat tilts dangerously. Rebalancing is simply moving people back to their proper seats to keep the boat level and safe.
Formula
Calculation
Target Value = Total Portfolio Value x Target Percentage
Amount to Trade = Current Value - Target Value (sell if positive, buy if negative)
Example: Your portfolio is worth $100,000 and your target for shares is 60%, so the target value is 100,000 x 0.60 = $60,000. Your shares are currently worth $75,000, so the amount to trade is 75,000 - 60,000 = $15,000 of shares to sell. Your bonds are worth $25,000 against a target of 100,000 x 0.40 = $40,000, so you buy $15,000 of bonds, and the portfolio returns to 60/40.
The drift here is 75% - 60% = 15 percentage points, well past a typical 5-point trigger. You can also rebalance without selling. If your portfolio is worth $100,000 with $65,000 in shares and $35,000 in bonds and you add $10,000 of new cash, the new total is $110,000, the target for shares is $66,000 and the target for bonds is $44,000. Buying $1,000 of shares and $9,000 of bonds restores 60/40 with no sale and no tax bill.Case study
Seen in the real world
This is a fictional, illustrative scenario. BrightSpark Logistics held a surplus reserve of $500,000 intended for future expansion. The finance committee set a conservative policy of 50% low-risk corporate bonds and 50% equity index funds. Over two consecutive years the equity funds surged, pushing the stock portion to 70% of the reserve, or $350,000, while bonds made up only 30%, or $150,000. Realising the business was now exposed to much higher market volatility than the board had approved, the finance manager started a rebalancing procedure.
They sold $100,000 of equity funds and reinvested the proceeds into corporate bonds. This brought the reserve back to $250,000 in each, the target 50/50 split. The test came the following year, when equities fell by 20% and bonds stayed flat. Without rebalancing, the $350,000 in equities would have lost $70,000, whereas the rebalanced $250,000 lost only $50,000. The $20,000 difference was kept in the reserve, which more than covered the modest tax and dealing costs of the original sale.
Watch out
Common mistakes
- Rebalancing too frequently, which racks up unnecessary transaction fees and tax liabilities.
- Panicking during a market drop and selling low instead of sticking to the long-term target.
- Failing to account for tax consequences when selling investments for a profit.
Questions
People also ask
How often should I rebalance my portfolio?
Most investors rebalance either once a year or whenever an asset drifts more than five percent away from its target allocation.
Does rebalancing always involve selling assets?
Not necessarily. You can also rebalance by directing new cash contributions entirely into the lagging asset class.
Is rebalancing expensive?
It can incur transaction costs or capital gains taxes, so it is best to plan rebalancing moves carefully to minimise expenses.