Portfolio rebalancing is the practice of returning your investments to their intended mix after market movement has pulled them out of alignment. It is one of the least glamorous parts of investment management and one of the most consequential, because a portfolio that drifts long enough stops reflecting the risk level you originally chose. Many investors in the Sacramento region are carrying considerably more stock exposure today than they intended, simply because they have not looked in a while.
What Portfolio Rebalancing Actually Does
Suppose you settled on a mix of 60 percent stocks and 40 percent bonds. If stocks gain 20 percent over a stretch while bonds gain 3 percent, that 60/40 portfolio becomes roughly 64/36 on its own. Nothing was bought or sold. Repeat that pattern across several strong years and the drift compounds: a portfolio that began at 60/40 can arrive at 75/25, which is a meaningfully different investment from the one you signed up for.
The purpose of rebalancing is not to increase returns. It is to control risk. The SEC describes the process as bringing a portfolio back to its original asset allocation mix, and it is candid about the emotional cost: rebalancing usually means trimming what has performed well and adding to what has lagged. You can read the agency’s plain-language treatment in its Beginners’ Guide to Asset Allocation, Diversification, and Rebalancing.
The risk of ignoring drift shows up asymmetrically. An over-weighted stock position feels fine while markets rise and feels very different during a decline, which is precisely when an unintended allocation does the most damage to a retirement plan that is close to drawing income.
Two Ways to Decide When to Rebalance
The calendar method
You review the portfolio on a set schedule, commonly every six or twelve months, and correct whatever has drifted. The advantage is simplicity. The date on the calendar is the reminder, and you are not tempted to react to headlines. The drawback is that a fixed schedule can miss a large move that happens between review dates.
The threshold method
You decide in advance how far an asset class may wander before you act, then rebalance only when that band is breached. A band of five percentage points is a common choice: a 60 percent stock target would be corrected once stocks reach 65 percent or fall to 55 percent. The advantage here is that the portfolio tells you when to act rather than the calendar. The drawback is that it requires you to actually monitor the allocation.
Neither approach is inherently superior, and a blended version works well for many households: check on a schedule, act only if a band has been breached. What matters far more than the specific rule is writing it down before the market gives you a reason to argue with it.
Three Ways to Execute a Rebalance
The SEC identifies three distinct mechanics, and the choice among them has real tax consequences.
- Sell and buy. Sell a portion of the over-weighted asset class and use the proceeds to purchase the under-weighted one. This is the fastest route and the one most likely to create a taxable event.
- Buy only. Direct new money into the under-weighted asset class until the target mix is restored. Nothing is sold, so nothing is realized.
- Redirect contributions. If you are still saving, change where your ongoing payroll deferrals or automatic transfers land, so that new dollars flow toward whatever is under-weighted until the portfolio corrects itself.
For a household still in the accumulation phase, the second and third options often do most of the work without a single sale. The SEC’s Director’s Take on rebalancing walks through the same three paths.
Test Your Rebalancing Instincts
Consider this situation, then open each option below to see how it works out. You hold the same 70 percent stock target across three accounts: a 403(b) at your district, a Roth IRA, and a taxable brokerage account. Stocks have run up and you are now at 78 percent. Where is the least costly place to do the selling?
A. The taxable brokerage account, because it is the most flexible
B. The 403(b) or the Roth IRA
C. Split the sale evenly across all three accounts
D. Do nothing and wait for the market to correct itself
Portfolio Rebalancing and Taxes in California
Inside a taxable brokerage account, a rebalance that involves selling appreciated positions is a taxable event. Two layers apply to California residents.
Federally, a position held more than one year receives long-term capital gain treatment at 0, 15, or 20 percent depending on taxable income, as described in IRS Topic No. 409. A position held one year or less is taxed at ordinary rates. For 2026, the IRS set the standard deduction at $32,200 for married couples filing jointly and $16,100 for single filers, with the top marginal rate of 37 percent beginning at $640,600 of income for single filers and $768,700 for joint filers, per the agency’s 2026 inflation adjustments.
At the state level, the calculation is simpler and less forgiving. The Franchise Tax Board states plainly that California does not have a lower rate for capital gains and that all capital gains are taxed as ordinary income. There is no preferential long-term rate to plan around in California, which raises the value of every technique that avoids realizing a gain in the first place.
Practical ways to lower the cost of a rebalance in a taxable account include directing new contributions toward the under-weighted asset class, taking dividends and capital gain distributions in cash instead of reinvesting them and using that cash to buy what is lagging, pairing a realized gain with a realized loss elsewhere in the account, and giving appreciated shares to charity rather than cash if you are already planning to donate.
Rebalancing Inside a 403(b), 457(b), or the TSP
Most employer plans used by California educators and federal employees offer an automatic rebalancing feature, often on a quarterly or annual schedule. Turning it on removes the discipline problem entirely for that account, and because the account is tax-sheltered, there is no tax cost to the trades.
One caution worth naming: a target-date fund already rebalances internally to its own glide path. Holding a target-date fund alongside several individual funds produces an allocation that is difficult to measure and easy to misjudge. If you use a target-date fund, it generally works best as the whole of an account rather than one holding among many.
The Part That Is Actually Hard
Portfolio rebalancing fails in practice for behavioral reasons, not technical ones. The rule asks you to sell the holding that has done best and buy the one that has done worst, which feels backward every single time. That is why we encourage clients to write the rule down in advance, in a sentence or two, and to treat the review as maintenance rather than as a forecast. A decision made in a calm moment holds up better than one made while watching a market move.
If you have not checked your allocation in more than a year, that is the place to start. Add the balances by asset class across every account you own, including old employer plans you have not touched, and compare the result to the mix you believe you have. The gap is often larger than expected.
Where We Can Help
We help clients set a target allocation that matches both their tolerance for volatility and their actual capacity to absorb it, then maintain that allocation across every account in the household in a tax-aware order. If you would like a second set of eyes on how far your portfolio has drifted, schedule a free 30-minute call at rooneywealth.com/contact. There is no cost and no obligation.
Rooney Wealth Management LLC is an investment adviser registered with the state of California. This article is for educational purposes only and is not tax, legal, or investment advice. Please consult your tax or financial professional regarding your specific situation.
