Editor’s note: This is general educational information about how India’s equity market halts work. It is not investment advice, it does not describe any specific event or security, and it is based on the official sources listed at the end.
Analysis: two mechanisms, two different problems
The two systems are often described together, but they are answers to different failures. A single stock band is a limit on information: it caps how far one company’s price can travel in a session, which contains the damage from an order error, a rumour or a sudden absence of liquidity on one side of the book. A market-wide halt is a limit on correlated selling, and its trigger is deliberately not a company at all but a benchmark, because the risk it addresses is that everything moves together faster than clearing and margin systems can keep up.
The design choices inside each mechanism follow from that difference. The market-wide breaker gets harder as the day goes on: a 10% move at 2:30 PM produces no halt, while a 15% move at 2 PM ends the session. That is a rule about what a pause is for. Early in the day a halt buys time for participants to reassess and return; late in the day there is not enough session left for reassessment to matter, so the choice is between trading on and closing. The single stock rules move in the opposite direction: the dynamic band widens step by step, by 5%, then 3%, then 2%, with the cooling off period lengthening from 15 minutes to 30 and then 60. A stock with a live derivatives market is not frozen, it is slowed, because the derivative provides another venue for price discovery and a hard freeze would only push the disagreement there.
The exclusion at the centre of the framework is the part worth reading closely. Stocks with derivatives are exempt from the fixed 20% band precisely because they have an alternative price discovery channel, and the ETF changes of June 2026 apply the same logic to funds, replacing a fixed band tied to a stale net asset value with a dynamic band tied to a traded price. The stated reason was the lag of one trading day in the base price and the fixed band not being commensurate with the price range of the underlying. A band is only as useful as the reference price it is measured from, and a band anchored to a stale reference can constrain a fund that is tracking an index moving freely.
Two things follow for anyone watching a halted market. First, the reference is the previous close, recomputed daily, so the rupee distance to a trigger changes every morning. Second, a market-wide halt purges every unmatched order in the system, which means resting orders do not survive the pause, and trading restarts through a fifteen minute call auction rather than continuous matching. What resumes is not the order book that stopped.
What the documents say
India’s equity market has two sets of brakes, and they work on different things. One stops a single stock from moving too far in a day. The other stops the entire market, in the cash and derivatives segments, when a benchmark index moves far enough. The rules for both are set by SEBI and carried in the master circular for stock exchanges and clearing corporations, and their triggers are recalculated every day from the previous close.
The market-wide halt
The index based market-wide circuit breakers apply at three stages of index movement either way, at 10%, 15% and 20%. They are triggered by movement of either the BSE Sensex or the NSE Nifty 50, whichever is breached earlier, so a halt on one benchmark stops trading on both exchanges. The exchanges translate those percentages into index levels each day, based on the previous day’s closing level of the index.
The length of the halt depends on the size of the move and the time of day. A 10% move produces a 1 hour halt before 1 PM, a half hour halt at or after 1 PM but before 2:30 PM, and no halt at all at or after 2:30 PM, when the market keeps trading. A 15% move produces a 2 hour halt before 1 PM, a 1 hour halt at or after 1 PM but before 2 PM, and a halt for the remainder of the day at or after 2 PM. A 20% move halts trading for the remainder of the day whenever it happens.
The mechanism is engineered as much as it is drafted. Exchanges compute their market-wide index after every trade in a constituent stock and check for a breach after every such computation. On a breach, the exchange stops matching orders and purges all unmatched orders from the system. Messages relating to market-wide circuit breakers must be given higher priority over other messages, and the systems and network used to compute the index, check the limits and issue the stop-matching instruction cannot be used for any other purpose. The mechanism must be reviewed within the exchange’s annual system audit. Trading resumes with a fifteen minutes pre-open call auction session, and the halt itself is shortened by fifteen minutes to accommodate it.
The single stock bands
Alongside the index mechanism, individual scrip wise price bands of up to 20% either way apply to all scrips in the rolling settlement, except those on which derivative products are available. Those excluded securities, meaning stocks with derivatives, index futures and stock futures, run on dynamic price bands, an operating range set at 10% of the previous day’s closing price, which rejects orders placed beyond the limits rather than freezing the stock outright.
The dynamic band is designed to widen under pressure rather than to hold. Under norms in a circular dated May 24, 2024, for the first two instances of flexing the band is widened by 5% of the previous close after a cooling off period of 15 minutes, or 5 minutes if the conditions are met in the last half hour of trading. For the next two instances the band widens by 3% after a cooling off period of 30 minutes, and for subsequent instances by 2% after 60 minutes. The stated purpose is to give participants time to absorb company or market specific news, producing orderly price movement and reducing strain on settlement systems.
Newly listed shares get their own treatment. For an issue size up to Rs. 250 crore, the first day price band in the normal trading session is 5% of the equilibrium price discovered in the call auction, or 5% of the issue price where no equilibrium price is discovered, and trading takes place in the trade-for-trade segment for the first 10 days. For an issue size greater than Rs. 250 crore, the same construction applies at 20%.
Exchange traded funds were moved onto a similar footing by a circular dated June 15, 2026. Equity and debt ETFs, other than overnight and liquid ETFs, move from a fixed band to dynamic price bands with an initial band of 10%, flexible up to 20% after a cooling off period, with the band flexed by 5% of the base price for a maximum of two instances in one direction, and only in the direction of the price movement. Overnight and liquid ETFs keep a fixed band of 5%, and commodity ETFs start at 6% and flex by 3%. The base price becomes the T-1 day closing price, defined as the last 30 minutes volume weighted average price, with the exchanges and asset management companies to implement the T-1 day closing net asset value as the base price with effect from April 01, 2027.
