Rebalancing with new money instead of selling

Drift is what markets do

You set a target mix, say 70% equity and 30% debt, because it matches how much risk you can bear. Then the market moves, and equity grows faster than debt. A year later your mix is 80:20. You did nothing wrong, but you are now carrying more risk than you chose, and a fall in equity will hurt more than you planned for.

The textbook fix is to sell some equity and buy debt. That works, but it has a cost: in a taxable account, a sale can trigger tax and sometimes an exit load. There is a gentler way when you are still investing: steer the new money to where the portfolio is short. Our guide on asset allocation and rebalancing covers the basics; this post is about the no-sale version.

A worked example

Assume a ₹10 lakh portfolio with a 70:30 target. Equity has grown, so you now hold ₹8 lakh in equity funds and ₹2 lakh in debt: 80:20. All numbers are illustrative.

Route 1: sell. To get back to 70:30 on ₹10 lakh you need ₹7 lakh of equity and ₹3 lakh of debt, so you sell ₹1 lakh of equity and buy ₹1 lakh of debt. Say that ₹1 lakh slice cost you ₹60,000, a gain of ₹40,000:

• If you held it 12 months or less, listed-equity and equity-fund gains are short-term, taxed at 20% as of October 2026: ₹8,000.
• If you held it more than 12 months, the gain is long-term, taxed at 12.5% only above ₹1.25 lakh of long-term gains in the year, so this ₹40,000 would be tax-free if it is your only such gain that year.

Check current rates and limits on the Income Tax Department site, and run your own case on the capital gains tax calculator. Selling also means an exit load if the fund charges one for units sold within a set period; check the scheme documents on the AMFI site or the AMC's page.

Route 2: add money to the lagging side. Keep the ₹8 lakh in equity untouched. How much debt do you need so that equity is 70%? Equity ₹8 lakh is 70% of a total of ₹8 / 0.7 = ₹11.43 lakh, so the debt must be ₹3.43 lakh. You hold ₹2 lakh, so you need ₹1.43 lakh of new money into debt and nothing out of equity.

If you invest ₹30,000 a month, redirecting the whole SIP to debt for about five months (₹1.5 lakh) restores the mix, assuming markets are flat. There is no tax, no exit load, and no market-timing decision. In a rising market, equity keeps drifting up in the meantime, so the redirect may need to run longer than the arithmetic says. The asset allocation calculator can recompute the gap each time you check.

When new money is the right tool

• You have an ongoing SIP or a regular surplus.
• The drift is moderate, say 5 to 10 percentage points.
• Your holdings are in a taxable account with large embedded gains.
• You would otherwise sell units still inside an exit-load window.

It is less suitable when the drift is large and you have no new money, when a single position has become a big share of the portfolio, or when you are close to a goal and need to lock in gains. The tactical asset allocation guide explains why deliberate deviation is a different decision from drift.

What to do with the leftover tax tools

Two related tools help when you do have to sell:

• Use losses. If another holding is at a loss, selling it can offset gains elsewhere. See the tax-loss harvesting calculator and our tax-loss harvesting guide.
• Stage the move. If you have to shift a lump sum between funds, a systematic transfer plan moves it gradually and the STP calculator models it. Remember that each transfer is a redemption and is taxable, which is why switching funds is a taxable event.

Debt fund gains are taxed at your slab rate as of October 2026, whatever the holding period, so a debt-heavy rebalance by selling debt is rarely cheaper than adding to it. Our post on capital gains on stocks and property puts the rates side by side.

Setting up the habit

1. Write the target and the band. For example, 70:30 with a five-point band. Our asset allocation by age post is a starting point for the target itself.
2. Check on fixed dates, such as a birthday and six months later, and not whenever the market is in the news.
3. If you are outside the band and still investing, redirect the SIP. If a SIP split across funds is easier to run, change the ratio rather than stopping.
4. If you are outside the band and not investing, decide whether the tax cost of selling is smaller than the risk you are carrying. Sometimes it is.
5. Automate what you can. A balanced advantage or hybrid fund rebalances inside the fund, and the robo-advisor versus DIY guide compares the options. Hybrid funds rebalance internally; the tax treatment of the fund depends on its equity share, so read the scheme documents.

The same logic helps you track your net worth every quarter: the quarterly check is a natural time to look at the mix too.

A last point on discipline. Rebalancing is deliberately boring: it makes you add to what has lagged and stop adding to what has run. That feels wrong when equity is rising and debt looks dull, which is exactly why a written rule helps. Without one, people postpone the correction until a fall makes it painful, and then sell in a panic. With one, the correction is a routine entry in a calendar. Keep a short note of each check (the date, the mix, the action taken) and you will have a record that shows whether the rule is working.

This post is for education only and is not investment or tax advice. Tax rates, exemptions and fund rules change; verify them with official sources and a tax professional.