Ibovespa closed at 197,323 points on April 10, 2026, posting a gain of 22% year-to-date. That same week, the South Korean KOSPI surged 5.68% over five sessions, and the S&P 500 hit all-time highs following the announcement of a ceasefire between Israel and Iran. Rallies like this are great for your net worth in the short term — but they create a structural problem most investors ignore: the portfolio you built at the start of the year is no longer the same one you have today.
Not in terms of returns. In terms of risk.
What Happens to a Portfolio During a Rally
Imagine you started 2026 with a 60% equities / 40% fixed income allocation — the classic 60/40 portfolio. In January, you had R$ 100,000. Your equity sleeve was R$ 60,000; fixed income, R$ 40,000.
Fast-forward four months. Ibovespa rises 22%. Your equity position — stocks or equity ETFs — grows from R$ 60,000 to roughly R$ 73,200. Fixed income, earning something close to 4.5% over the period (Tesouro Selic or a floating-rate CDB), moves from R$ 40,000 to R$ 41,800.
The total portfolio climbs from R$ 100,000 to R$ 115,000 — great. But now the split looks like this:
| Asset class | Value | Current weight | Target weight |
|---|---|---|---|
| Equities | R$ 73,200 | 63.6% | 60% |
| Fixed income | R$ 41,800 | 36.4% | 40% |
The portfolio has drifted. You planned 60/40 and are now running 63.6/36.4 in practice. Three and a half percentage points may sound marginal, but in a R$ 500,000 portfolio that's R$ 18,000 more in risk than you originally decided to take on.
What if the rally continues at the same pace for another six months? That same portfolio would sit at 68/32 — nearly 70/30. You'd have migrated to an aggressive risk profile without ever consciously making that decision.
Why Drift Matters Before Corrections Hit
Strong rallies rarely travel in a straight line. A market that climbs 22% in four months carries within it the pressure of a technical correction. An investor running 63.6% in equities — instead of the planned 60% — is most exposed precisely when the risk of a reversal is highest.
Rebalancing exists to solve this problem: bringing the portfolio back to its original risk profile, using the process of "selling what has appreciated and buying what has lagged." This is not about calling the top. It's allocation discipline.
Two Methods: Calendar-Based and Threshold-Based
There are two main approaches for deciding when to rebalance:
Calendar-based rebalancing: you pick a fixed frequency — annual, semi-annual, or quarterly — and readjust on that date regardless of where markets stand. Simple to execute, easy to plan.
Threshold-based rebalancing: you define a tolerance band — commonly a 5% drift in any asset class — and readjust whenever any holding exceeds that limit, regardless of the date. More dynamic, more responsive to sharp moves.
Academic evidence favors the threshold approach for tax-conscious investors: it concentrates transactions at moments when the imbalance is genuine, reducing the number of trades and, consequently, taxable events. For a portfolio subject to Brazilian income tax, trading less often is a concrete advantage.
In practice, many professional managers combine both: they review on a schedule (quarterly, for example) but only rebalance if the drift exceeds the defined limit. This avoids unnecessary transactions during sideways markets.
The Mechanics of Rebalancing
Given the scenario above — portfolio at 63.6/36.4 with a 60/40 target on R$ 115,000 — the math is:
| Asset class | Current balance | Target balance (60/40) | Adjustment needed |
|---|---|---|---|
| Equities | R$ 73,200 | R$ 69,000 | Sell R$ 4,200 |
| Fixed income | R$ 41,800 | R$ 46,000 | Buy R$ 4,200 |
In the context of Ibovespa above 197,000 points, this translates to: trim your BOVA11 position or your best-performing individual stocks, and redirect the proceeds into Tesouro Selic, a floating-rate CDB, or Tesouro IPCA+. You sell what got expensive and buy what got cheaper in relative terms.
There's a second, more efficient approach for those who make regular contributions: instead of selling the appreciated assets, redirect all new money exclusively to the underweight asset class. If you invest R$ 2,000 per month and fixed income is below target, put the next R$ 2,000 entirely into fixed income. No sale, no capital gain realized — therefore, no taxable event.
This method is slower, but far more tax-efficient for portfolios in the accumulation phase.
Brazilian Tax Treatment: What Changes With Rebalancing
This is where the rebalancing strategy meets the reality of Brazilian income tax — and where choosing between "sell" and "redirect new contributions" makes a real difference.
Individual stocks: there is a capital gains tax exemption for monthly sales up to R$ 20,000. Sales above that threshold are taxed at 15% on the capital gain (regular transactions) or 20% (day trades), paid monthly via DARF.
ETFs (BOVA11, IVVB11): the R$ 20,000/month exemption does not apply to ETFs. Any capital gain on the sale of ETF shares is taxed at 15%, regardless of the amount.
Fixed income (Tesouro Direto, CDBs): income tax is withheld at source upon redemption, with declining rates that reach 15% for maturities beyond 720 days. There's no taxable event at purchase — only at redemption.
In practice, for an investor rebalancing a R$ 115,000 portfolio by selling R$ 4,200 in BOVA11 at a proportional gain, the tax would be calculated on the average cost basis of the shares sold — and would hit at 15% with no exemption. For individual stocks of the same amount, if total monthly sales don't exceed R$ 20,000, the gain is tax-free.
This tax difference is a real argument for structuring rebalancing via new contributions whenever possible, reserving sales for situations where the drift is too large to be corrected organically by cash flow.
Tip
If you use ETFs as the core of your portfolio and need to rebalance, consider making the adjustment on the fixed-income side: redeem what's above target in bonds with a lower marginal tax rate (long-dated Tesouro Selic already has a 15% rate) instead of selling the ETF. The net effect on your allocation is the same; the tax cost may be lower.
How Much Drift Justifies Action?
There's no universal answer, but the reference I use in managing positions is this:
- Drift below 3%: tolerate it and correct with new contributions. Transacting for a small adjustment doesn't justify the brokerage cost and potential tax hit.
- Drift between 3% and 5%: evaluate. If contributions are expected in the next 30–60 days, use them to correct. If not, consider a partial rebalance.
- Drift above 5%: rebalance. Your risk exposure is now materially different from what you planned. Staying put is an active decision to take on more risk — not a passive decision to maintain the status quo.
With Ibovespa up 22% in four months, any portfolio with meaningful exposure to Brazilian equities is probably above the 5% threshold relative to target. This is precisely the scenario that makes rebalancing relevant right now — not as a theoretical exercise.
Rebalancing Is Not Market Timing
The most common objection I hear: "But if I sell now and the market keeps climbing, I miss out on the gain."
This objection confuses rebalancing with market timing. You're not exiting the market. You're adjusting the proportion of each asset class back to the risk profile you decided was right for you. Equities stay in the portfolio — they just return to their correct weight.
If the market keeps rising, the equity sleeve (now at target weight) will capture those gains. If it corrects, the portfolio will be better positioned than it was with accumulated drift. In either scenario, the portfolio is operating within the risk profile it was designed for.
That's different from trying to predict whether Ibovespa goes to 220,000 or corrects to 170,000. Rebalancing doesn't require an opinion on the market. It only requires checking the weights and comparing them to the target.
At Royal Binary, Sidnei Oliveira manages short-term variable income operations with risk discipline applied to every position — a component that, within a diversified and rebalanced portfolio, operates in a decorrelated way from buy-and-hold assets. Want to understand how it works? Access the platform.