IEX Market Coupling Delayed: Why It Is Now 1.5 to 2 Years Away, and What That Means for the Stock

Market coupling was supposed to start in January 2026. It hasn't, and it won't this year either. On October 29, Indian Energy Exchange (IEX) management said coupling is "definitely not likely this calendar year" and could take another 1.5 to 2 years. The final regulations have still not been notified, even though the regulator told the Supreme Court in August they would come shortly. This post explains what market coupling is, why it keeps slipping, what the draft rules actually say, how much profit is at stake for IEX, and what every year of delay is worth to shareholders.

Market coupling, explained simply

India has three power exchanges: IEX, PXIL and HPX. Today each runs its own auctions. Buyers and sellers place bids on an exchange, and that exchange matches them and sets its own price.

IEX handles roughly 85 to 90% of all exchange-traded electricity. Liquidity attracts liquidity: the exchange with the most buyers and sellers usually gives the best price and the surest fill, so almost everyone trades there. That loop is IEX's moat.

Market coupling breaks the loop. Each exchange would still collect bids from its own members, but it would pass them to one central Market Coupling Operator. That operator runs a single combined auction and sets one price for the whole country. A buyer would get the same price on IEX, PXIL or HPX. The exchanges would then compete on fees, technology and service rather than on liquidity.

An analogy: today India has three marketplaces and almost everyone shops at the biggest one, because it has the most sellers and the best prices. Coupling is like pooling every seller's stock into one shared warehouse, with the same price at every shop's counter. The biggest shop still has the most customers walking in, but it can no longer claim a better price.

Why the regulator wants it

• One national price. Fragmented markets can show different prices for the same hour. A single price is a cleaner signal for investment in generation and storage.
• Better use of transmission. A combined auction can allocate cross-region transmission capacity across all bids at once.
• Competition. The regulator worries that one exchange dominating price discovery is unhealthy. In August 2026, the Supreme Court remarked that the power exchange segment appeared to be "in need of regulation."
• The case against: IEX argues it won its share by building a better product, and that coupling punishes success. Critics also point out that exchanges handle less than 10% of India's electricity. When the grid operator test-ran coupling on historical data, the gains were tiny: about a 0.3% improvement in economic welfare in the day-ahead market (around ₹38 crore) and about 0.01% in the real-time market.

How we got here: the full timeline

What the April 2026 draft says

The draft is the CERC (Power Market) (Second Amendment) Regulations, 2026. Its key points:

1. Grid India is the sole Market Coupling Operator. The 2025 plan for the three exchanges to take turns running the auction has been dropped. Price discovery moves to a neutral, state-owned operator, which must set up a dedicated cell to do it.
2. DAM and RTM are both in scope. The day-ahead market (DAM) and the real-time market (RTM) can both be coupled, with other segments to follow. Each segment gets its own start date, to be notified separately. The 2025 order had planned DAM first and RTM only after experience with DAM.
3. Exchanges become order collectors in coupled markets. They must collect bids in a standard format, validate and anonymise them, and send them securely to Grid India on strict timelines. Grid India takes over the IT, data, information and surveillance duties that the exchanges carry today for price discovery.
4. One price, split only when the grid is congested. The operator maximises total economic surplus across all bids. Without congestion, the whole country gets one clearing price. When transmission between regions is congested, the market splits into regional prices.
5. The detailed rulebook comes later. Grid India has six months after notification to write the Power Market Coupling Procedure, which CERC must then approve. That procedure will cover bid formats and encryption, the algorithm, scheduling, settlement, and the operator's own charges.

Why it is taking so long, and why 1.5 to 2 years is realistic

Even if CERC notified the final regulations tomorrow, a long checklist would remain:

1. Notification. CERC told the Supreme Court in August that the regulations would be issued shortly. About three months later, they still have not been.
2. Six months to write the rulebook. Grid India's coupling procedure is due within six months of notification, then needs CERC approval.
3. Build and test. Grid India has to build a national matching engine. Three exchanges with different systems have to connect to it, and clearing and settlement must be redesigned so one auction can settle across three exchanges. The software needs audits, and a steering panel was recommended for this in June 2026. Then come mock trials, and only then live trading.
4. Legal challenges. Both the tribunal and the Supreme Court said IEX can challenge the regulations once they are final. Expect it to, and expect at least one more round in court.
5. RTM is a moving target. A separate proposal would cut RTM's gate closure, the gap between the last bid and delivery, to 50 minutes. Fitting a central coupling step into an even shorter window is much harder, so RTM coupling is likely to lag DAM by a long way.

Rough maths: notification around early 2027, the procedure written and approved by late 2027, then build, mock trials and any litigation. That puts DAM coupling in late 2027 or 2028, which matches management's 1.5 to 2 years. RTM would come later still.

How much of IEX is exposed

In Q2 FY27 (July to September 2026), IEX traded 39.7 billion units of electricity:

So about 37% of volume is exposed in the first phase, and close to 80% if RTM follows. Outside coupling altogether are RECs, IGX (the gas exchange, regulated by a different body, PNGRB), ICX's international certificates, the coal exchange IEX has applied for, and new markets such as capacity, ancillary services and carbon.

What coupling could do to IEX's profit: our scenarios

IEX charges about 2 paise per unit from the buyer and 2 paise from the seller. At the current run-rate of about 154 billion units a year, every 1 paisa of total fee is worth roughly ₹155 crore of revenue, or about ₹115 crore after tax. That is about a fifth of IEX's annualised profit.

Coupling hurts through two channels:

• Lost share: once prices are the same everywhere, some volume moves to cheaper exchanges.
• Fee pressure: IEX may cut fees to hold on to members, and the coupling operator may add a charge of its own.

These are our illustrations, not forecasts. They assume today's volumes and cost base, and they leave out growth. Volume has been growing in double digits, which would cushion any of these cases over a two-year wait.

What the delay is worth

• IEX at ₹105 (October 29 close) is valued at about ₹9,400 crore, or roughly 17 times annualised first-half profit of ₹548 crore.
• Each year without coupling is another year of roughly ₹550 crore of profit at full margins, about 6% of IEX's market value. A two-year delay is worth around 12%, before counting volume growth.
• The stock has not been rewarded for the delay. It fell from about ₹169 before the July 2025 order to about ₹124 by late August 2026 and about ₹105 now, even as the deadline kept slipping. The market is valuing IEX as if the base or severe case is certain. Hesitation is not cancellation, so nobody is paying for the chance that coupling never comes.
• Cash and IGX cushion the downside. IEX holds about ₹1,200 crore of cash and will raise more by selling part of its IGX stake in the coming IPO. Management said it will consider a buyback. Cash plus the IGX stake is roughly 30% of IEX's market value.

What would change the timeline

Faster:

• CERC notifies the final regulations soon, and the courts decline to stay them.
• Grid India writes its procedure well inside six months.
• The regulator decides to couple DAM alone first, with a short mock-trial period.

Slower:

• A court stays the regulations after IEX challenges them.
• Software audits or mock trials show problems, especially with settlement across three exchanges.
• The RTM gate-closure change goes through, making real-time coupling harder.
• Pushback from discoms or generators on the operator's charges.

What it means for IGX unlisted shareholders

Market coupling is a power-market rule set by CERC. It does not apply to Indian Gas Exchange (IGX), which is regulated by PNGRB. For IGX, the coupling story matters in two ways:

1. It is part of why the IGX IPO matters to IEX. Diversification beyond power is IEX's main answer to coupling. A listed IGX will put a daily market price on the roughly 25% stake IEX keeps.
2. IGX's own risks are different. For IGX, watch gas pricing, GST and LNG supply, not coupling.

Our full post on IEX's Q2 results and the IGX IPO covers the IGX offer for sale, valuation and lock-in. Live unlisted price and lot size are on the Indian Gas Exchange share page.

Frequently asked questions

When will market coupling start in India? No start date has been fixed. The final regulations were still not notified at the end of October 2026. IEX management estimates 1.5 to 2 years, which points to late 2027 or 2028 for the day-ahead market.

Will IEX shut down or lose all its business under coupling? No. IEX would still collect bids from its members, run its other markets and charge transaction fees. The risk is lower market share and lower fees in the coupled markets, not the end of the business.

Who will run the coupled market? Under the April 2026 draft, Grid India, the national grid operator, would be the sole Market Coupling Operator.

Has IEX lost its court cases? Not on the merits. The appeals tribunal and the Supreme Court both said IEX's challenges were premature, because coupling can only be implemented through final regulations. IEX can challenge those regulations once they are notified.

Does market coupling affect IGX? No. IGX is a gas exchange regulated by PNGRB, and coupling applies only to power markets regulated by CERC.

The bottom line

Market coupling is real, but it is slow. Fifteen months after the order and ten months after its own January 2026 deadline, the rules are still only a draft. After they are notified, Grid India still needs six months for its rulebook, then the system must be built and tested, and the rules will very likely be challenged in court. Management's 1.5 to 2 years looks realistic, and the first phase covers just over a third of IEX's volume. At about ₹105, the stock already prices in heavy damage. Each year of delay adds about 6% of IEX's value in profit, and the cash, the IGX stake and a possible buyback add a cushion. The risk to watch is the fine print of the final regulations: how many markets they cover, what the operator charges, and whether fees are capped.

Disclaimer: This article is for information and education only and is not investment advice. Regulatory history and the draft provisions are summarised from CERC proceedings and IEX's disclosures up to October 31, 2026. The IEX share price is the NSE close on October 29, 2026. Market-share figures are approximate. Fee sensitivity, profit scenarios and the value of delay are ShareSaathi's own calculations on first-half FY27 run-rates, and are illustrations, not forecasts. Please consult a SEBI-registered investment adviser before investing.