Merger Swap Ratio: How Many New Shares You Get When Two Listed Companies Combine

When a company you own announces it is merging into another listed company, the first number everyone hunts for is the merger swap ratio. It tells you how many shares of the surviving company land in your demat account for every share you give up. Get it wrong and you misjudge what your holding is really worth. Get it right and you can read a merger announcement in about two minutes.

We’ll walk through what the ratio is, how Indian valuers arrive at it under SEBI’s rules, how to work out your own entitlement, and why the two stocks rarely trade exactly at the ratio. There’s a real example from this month’s filings at the end.

What a merger swap ratio actually means

A swap ratio, also called the share exchange ratio, is the rate at which the acquiring company hands out its own shares in exchange for the target company’s shares. Investopedia’s explainer puts it simply: a 2:1 ratio means two acquirer shares for every one target share. The target’s shares usually stop existing once the deal is done, and you’re left holding the acquirer’s stock at the acquirer’s price.

Indian announcements tend to spell the ratio out in words, often in the form “X shares of the transferee for every Y shares of the transferor”. The transferee is the company that survives. The transferor is the one being absorbed. So “21 for every 4” means 5.25 new shares per old share. Always convert it to a per-share figure before you do anything else. It saves a lot of confusion later.

One trap: face value doesn’t decide anything here. A ₹10 face value share can be swapped for several ₹1 face value shares, and that tells you nothing about whether the deal is generous. What matters is the value per share on each side, which is where the valuers come in.

Who sets the swap ratio, and how SEBI wants it done

The ratio isn’t picked by the promoters over coffee, at least not on paper. SEBI’s Master Circular on Scheme of Arrangement (June 20, 2023) lays down the process for listed companies. A few requirements matter most to a shareholder:

• Valuation report. Listed entities must file a valuation report from a Registered Valuer, a person registered under Section 247 of the Companies Act, 2013. The report has to show the workings, the relative fair value per share and the fair share exchange ratio. It isn’t needed where the listed entity’s shareholding pattern doesn’t change.
• Fairness opinion. An independent SEBI-registered merchant banker has to give an opinion on the valuation done for the listed and unlisted entities. Neither the valuer nor the merchant banker counts as independent if there’s a material conflict of interest, such as common directorships or partnerships.
• Audit committee and independent directors. The audit committee recommends the draft scheme after considering the valuation report, and has to comment on the need for the merger, its rationale, synergies, impact on shareholders and cost-benefit. A committee of independent directors must also recommend it, keeping in mind that it isn’t detrimental to shareholders.
• Public shareholder vote in some cases. Where the scheme involves the promoter group or related parties in specific ways listed in the circular, it can be acted upon only if public shareholders’ votes in favour outnumber their votes against.

After that, the stock exchanges issue an observation letter, shareholders and creditors vote, and the National Company Law Tribunal (NCLT) has to sanction the scheme. Only then does the swap actually happen.

The swap ratio is not a market price. It’s a negotiated, valuer-backed number fixed months before the shares are actually issued, and the market spends those months deciding how much to trust it.

How valuers build the ratio: a worked example

The circular’s Annexure II gives the format. Each company is valued using three approaches (asset, income and market), each value gets a weight, and the weighted values give a relative value per share. Divide one by the other and you have the ratio, rounded off.

Here’s an illustrative version with made-up numbers. Say Alpha Ltd is absorbing Tara Ltd, and the valuer uses weights of 20% for the asset approach, 40% for income and 40% for market for both companies.

Alpha’s weighted value is 36 + 104 + 96 = ₹236. Tara’s is 280 + 500 + 460 = ₹1,240. One Tara share is therefore worth 1,240 ÷ 236 = about 5.25 Alpha shares. The valuer would round this to something clean, such as “21 Alpha shares for every 4 Tara shares”.

Notice how much the weights matter. If the valuer had put 50% on the asset approach, Tara’s book-heavy value of ₹1,400 would have pulled the ratio up. That’s why it’s worth reading the valuation report, not just the headline ratio. Minority shareholders sometimes push back precisely on the choice of weights.

Working out your own entitlement

The arithmetic is just multiplication. Using the 21-for-4 example, a holder of 400 Tara shares gets 400 × 21 ÷ 4 = 2,100 Alpha shares.

Odd holdings throw up fractions. Someone with 150 Tara shares works out to 150 × 21 ÷ 4 = 787.5 Alpha shares. Nobody gets half a share in a demat account. The scheme document has a clause on fractional entitlements that says what happens to the leftover bit, so look for it. If a cash payout for fractions is part of the deal, it’ll be described there, along with how it’s worked out.

Two more checks before you count your new shares:

• Record date. The board fixes a record date, and only those holding the transferor’s shares in their demat account on that date get the new shares. With T+1 settlement, a purchase has to settle by the record date to count.
• Listing of new shares. The new shares can trade only after the exchanges approve their listing and trading, so there’s usually a gap where your old shares have stopped trading and the new ones haven’t started.

Why the two stocks don’t trade at the ratio

Once a ratio is announced, you’d expect the target to trade at exactly ratio × acquirer price. It rarely does. Let’s go back to the illustration. Suppose that a few weeks after the announcement Alpha trades at ₹250 and Tara at ₹1,240.

• Implied value of one Tara share: 5.25 × ₹250 = ₹1,312.50
• Gap: ₹1,312.50 − ₹1,240 = ₹72.50
• As a percentage of Tara’s price: 72.50 ÷ 1,240 = about 5.8%

That 5.8% is the arbitrage spread. It exists because the deal isn’t done until NCLT signs off and the shares are issued, which can take many months. There’s the risk the scheme gets modified or blocked, the money tied up in the meantime, and the chance Alpha’s price falls before you can sell the new shares. Traders who buy Tara and short Alpha in the ratio are betting the spread closes. A wide spread usually means the market has doubts about timing or approval. A spread near zero means the market thinks the deal is as good as done.

For a long-term holder, the useful question is simpler: is the ratio fair? Compare it with what each business earns, how fast it’s growing and what it owns. A ratio that hands you fewer shares than the relative earnings justify is a transfer of value away from you, even if the press release calls it “value accretive”.

If the target already trades at a fat discount to the swap-implied value, the market is telling you something about the deal’s odds. Don’t ignore it just because the ratio looks generous on paper.

What happens to the acquirer’s shareholders

The swap ratio cuts both ways. New shares mean dilution for the acquirer’s existing holders, and how much depends on the size of the target and whether the acquirer already owns part of it.

Take the illustration a step further. Alpha has 100 crore shares. Tara has 10 crore shares, of which Alpha already owns 6 crore. Assume the scheme cancels the shares Alpha already holds instead of swapping them, so only the 4 crore minority shares get the 21-for-4 treatment. Whether that happens in a real deal is spelt out in the scheme document. That’s 4 crore × 5.25 = 21 crore new Alpha shares. Alpha’s share count goes to 121 crore, and Tara’s old minority holders end up with 21 ÷ 121, or about 17.4% of the enlarged Alpha.

Whether that dilution hurts Alpha’s holders depends on whether they’re getting at least 17.4% more earnings and assets in return. That’s the same test, viewed from the other side. Our guide to analysing quarterly results is a good place to start when you’re comparing the two companies’ numbers.

A real example: Dr Agarwal’s 23-for-2 merger

Here’s one in motion right now. On October 20, 2026, Dr. Agarwal’s Health Care Limited (AHCL) told the exchanges that its scheme to absorb listed subsidiary Dr. Agarwal’s Eye Hospital Limited (AEHL) becomes effective on November 1, 2026, with an appointed date of April 1, 2026, after the NCLT sanctioned it by an order dated September 30, 2026. The AHCL board outcome filed with NSE fixes Wednesday, November 18, 2026 as the record date, and repeats the ratio: 23 fully paid-up AHCL shares of ₹1 face value for every 2 fully paid-up AEHL shares of ₹10 face value.

Convert that to a per-share number and it’s 11.5 AHCL shares per AEHL share. So 100 AEHL shares become 1,150 AHCL shares. A holding of 15 AEHL shares works out to 172.5, which is where that fractional clause comes into play. AEHL’s own filing with BSE confirms the company stands dissolved from the effective date. We covered the dates in detail in our Dr Agarwal’s merger record date story.

It’s also a neat illustration of the face value trap. Twenty-three ₹1 shares for two ₹10 shares sounds lopsided until you remember that face value has nothing to do with market value.

A quick checklist when a merger is announced

• Convert the ratio to new shares per old share.
• Multiply by the acquirer’s current price and compare with the target’s price. That’s your spread.
• Open the valuation report and look at the approaches and weights used.
• Read the fairness opinion and the audit committee’s reasons.
• Find the clause on fractional entitlements if your holding won’t divide cleanly.
• Note the record date, and remember your new shares won’t be tradeable until listing approval comes through.
• If you hold the acquirer, work out the dilution and ask whether it’s paid for.

Mergers are the cousin of demergers, where one company becomes two. If you want the reverse case, our explainer on demerger of company shares walks through how cost and entitlements split.

Disclaimer: This article is for education only and is not investment advice. The Alpha Ltd and Tara Ltd figures are illustrative. Regulatory details are from SEBI’s master circular and the company filings linked above. Please do your own research or speak to a SEBI-registered adviser before acting on any corporate action.