Circuit Limits in Indian Markets: The Real 10%, 15% and 20% Rules

What a Circuit Limit Actually Is

A circuit limit is a hard ceiling and floor on how far a price can move in a single trading session before the exchange pauses or stops trading. India runs two separate systems that people often confuse. The first is the market-wide index circuit breaker, which halts the entire market when the Nifty 50 or the BSE Sensex moves sharply. The second is the individual security price band, which freezes trading in one stock when that single stock moves too far from its previous close.

Both systems exist for the same reason: to force a cooling off period during panic or mania so that orders are not filled at irrational prices and so the clearing system is not overwhelmed. They are mandated by the Securities and Exchange Board of India, known as SEBI, and enforced by the National Stock Exchange and the Bombay Stock Exchange. The rules are public and the trigger levels are fixed in advance, so there is no discretion on the day. The exchange simply applies the published thresholds.

The most important practical point is that these are not the same as a stop loss. A circuit halt protects the market as a whole. It does nothing to protect your individual trade, and once trading resumes the price can gap straight through your intended exit.

The Real 10%, 15% and 20% Index Tiers and Exact Halt Durations

This is the part most explainers get wrong, so here it is precisely. India uses a three stage market-wide circuit breaker at 10%, 15% and 20% movement in either direction, calculated on the previous day closing value of the Nifty 50 or the Sensex. The breaker triggers on whichever index crosses its threshold first. The halt is market-wide, meaning the cash segment and the equity derivatives segment both stop.

The crucial nuance is that the halt length is not fixed per tier. It depends on the time of day the breach happens. The published SEBI and exchange schedule is set out in the table below. Treat these as the current operating rules and always confirm on the NSE or BSE site before relying on them for a live trade.

Reading that table carefully matters. A 10% fall at 10:30 AM pauses trading for 45 minutes and then the market reopens. The exact same 10% fall at 3:00 PM does not halt the market at all, because after 2:30 PM the 10% tier no longer carries a halt. A 15% move after 2:00 PM closes the market for the day, but the same 15% move at 11:00 AM only pauses it for 1 hour and 45 minutes. And a 20% move shuts the market completely, no matter what time it happens. After every halt that is not a full closure, the exchange runs a 15 minute pre-open call auction to discover a fresh opening price before continuous trading restarts.

Why the Halt Locks the Whole Market, Not Just One Stock

When the index breaker fires, every equity stops. You cannot trade the falling stock, you cannot trade a defensive stock, and you cannot trade the index futures or options either. This is deliberate. During a true panic, allowing derivatives to keep trading while the cash market freezes would create a disconnected, manipulable price. So the equity cash and equity derivatives segments halt together.

Currency derivatives and commodity derivatives operate under separate rules and are not automatically halted by an equity index breaker, though severe cross market stress often spills over. For a stock and index trader, the practical takeaway is simple: when the breaker hits, your hedge in Nifty options is frozen at exactly the moment you most want to adjust it.

• The market-wide breaker is triggered by the Nifty 50 or the BSE Sensex, whichever crosses first.
• It is computed against the previous trading day closing index value, not the day open.
• It halts both the cash and equity derivatives segments at the same time.
• After a non-closing halt, a 15 minute pre-open call auction sets the reopening price.
• A 20% move closes the market for the rest of the session with no reopening.

Individual Stock Price Bands Versus Index Breakers

Separate from the index breaker, each individual stock has a daily price band, often loosely called its circuit. Common bands are 2%, 5%, 10% and 20%, set by the exchange based on the stock liquidity, surveillance status and whether it is in the derivatives segment. When a stock rises to the top of its band it is on the upper circuit, and when it falls to the bottom it is on the lower circuit.

A vital detail for serious traders: stocks that are part of the Futures and Options segment, along with large index constituents, generally do not carry a fixed 5% or 10% band. Instead they trade with dynamic price bands that start wide, for example 10% or 20%, and which the exchange can flex further in steps during the session if there is heavy one directional order flow. This is why a heavyweight like Reliance or HDFC Bank can move more than 10% on a results day without locking, while a small illiquid stock locks at 5% on the first burst of buying.

Worked Example: A Lower Circuit Trap in a Cash Stock

Numbers below are illustrative and not a forecast or a promise of any return. Suppose a mid cap stock, call it Stock A, closed yesterday at Rs 200 and carries a 10% daily price band. Today its lower circuit is Rs 180 and its upper circuit is Rs 220. Bad news hits and within minutes every buyer disappears at Rs 180. The stock is now locked at the lower circuit. There are millions of sell orders at Rs 180 and almost no buyers.

Say you bought 1,000 shares at Rs 200, an investment of Rs 2,00,000. On paper your loss at the Rs 180 lock is Rs 20 per share, or Rs 20,000, which is a 10% drawdown. But the real danger is that you cannot sell. Your sell order joins a giant queue at Rs 180 and never executes. The next day the band resets around the new close. If the stock opens locked at the lower circuit again, the price band steps down to roughly Rs 162, and your unrealised loss deepens to about Rs 38,000 even though you never got a chance to act.

On the tax side, remember the rules if you do eventually sell at a loss. For listed equity held under 12 months, this is a short term capital loss and short term capital gains on equity are taxed at 20%. A realised short term loss here can be set off against other short term or long term capital gains under the prevailing rules. If you were trading this intraday or through F&O, the profit or loss is instead treated as business income and taxed at your slab rate, not under capital gains. This distinction changes both your tax and your loss set off options.

Worked Example: Index Breaker Hits Your Nifty Options

Again, these figures are illustrative only. Assume the Nifty 50 closed yesterday at 24,000. The 10% market-wide breaker level is therefore a fall to 21,600, the 15% level is 20,400 and the 20% level is 19,200. A severe global shock opens the market sharply lower and by 11:15 AM the Nifty is down 10% at 21,600. Because the breach is before 1:00 PM, trading halts for 45 minutes, then a 15 minute pre-open auction runs, then continuous trading resumes.

Now suppose you were short one lot of a Nifty weekly 23,500 put, written for a premium of Rs 120. The Nifty lot size is 65, so you collected 120 times 75, which is Rs 9,000 in premium. During the halt you cannot adjust, exit or hedge anything. When trading resumes after the 10% halt, the put is deep in the money and its premium has exploded to, say, Rs 2,250. To close you must now pay 2,250 times 75, which is Rs 1,68,750. Your loss on this single short option is roughly Rs 1,59,750 before costs, a brutal outcome driven by the gap and the frozen window.

Costs add to the pain. On the sell legs you pay Securities Transaction Tax, known as STT, at 0.15% of the option premium on the sell side, plus exchange transaction charges, GST on brokerage and charges, SEBI turnover fees and stamp duty. As an option writer this is business income, so the net loss is set off against business income and taxed at your slab, not as capital gains. The lesson is that an index breaker does not save a leveraged short. It traps it. Defined risk strategies, where your maximum loss is capped by a bought option, behave far better through a circuit halt than naked shorts.

• During any index halt you cannot enter, exit, modify or hedge in the equity and equity derivatives segments.
• Premiums can gap violently across the halt, so a position reopens at a very different price.
• Naked or undefined risk option shorts are the most dangerous positions to hold into a breaker.
• Buying a protective option to cap your loss converts an open ended risk into a known, survivable one.
• Option writing profit or loss is business income taxed at your slab rate, not capital gains.

Expiry Day, Circuits and Weekly Options

Circuit risk is sharpest on expiry days. Index weekly options expire on a fixed weekday and monthly contracts expire on the last expiry day of the month, with premiums of at the money options decaying fast in the final hours. If a market-wide breaker fires late on an expiry afternoon, you can be locked out at the exact moment your option needs managing, and a 15% breach after 2:00 PM would close the market entirely, leaving your position to settle as it stands.

This is why experienced traders avoid carrying large, undefined risk expiry positions into the last 30 to 45 minutes of a volatile session. The combination of fast time decay, thin liquidity and the chance of a late day halt is a poor risk to take. If you must hold into the close on a turbulent day, a defined risk spread is far safer than a naked option, because your worst case is already known and capped.

How These Rules Were Tested in Real Crashes

India has seen the market-wide breaker fire in genuine stress. The most cited example is March 2020, during the COVID-19 sell off, when both the Sensex and the Nifty 50 fell so hard at the open that the 10% lower breaker was triggered and trading was halted for 45 minutes before resuming. The system worked exactly as designed: a forced pause, a pre-open auction and an orderly restart, rather than a chaotic free fall.

The lesson from these events is not that circuits make the market safe. It is that they slow a crash down, give participants a structured pause and prevent a complete breakdown of price discovery. For a trader, the takeaway is that circuit halts cluster precisely when your positions are most stressed, so your risk plan has to assume that you might be unable to act for the length of a halt or even for the rest of the day.

Trading Around Circuits Without Getting Hurt

Practical risk control around circuits is mostly about position size and structure, not prediction. You cannot reliably forecast the breach that triggers a halt, but you can make sure no single halt can ruin you. That means sizing so a multi session lower circuit run in a cash stock is survivable, and avoiding undefined risk shorts that can blow out across an index halt.

• Know each stock daily price band before you trade it, especially small and mid caps that lock at 5%.
• Avoid pyramiding into a stock that is repeatedly hitting upper circuits on thin volume, because the unwind can be just as violent.
• Prefer defined risk option structures over naked shorts so a halt cannot create an open ended loss.
• Keep leverage modest into known event days such as results, budget and major global data.
• Treat your stop loss as a plan, not a guarantee, because a locked circuit can leave it unfilled.

Sources and Further Reading

For authoritative and current details, always check the official sources directly, since trigger levels, halt durations and price band rules can be revised. Refer to SEBI, NSE India and BSE India for the live market-wide circuit breaker schedule, individual stock price bands and contract specifications before you trade.

Sources and Further Reading

For authoritative data and further reading on this topic, refer to SEBI (Securities and Exchange Board of India), NSE India and BSE India. Always confirm current rules, rates and contract specifications on the official source before you trade.