Circuit Breakers in the Stock Market: The Market-Wide Halt Rules
“Circuit breaker” gets used for two completely different mechanisms in Indian markets, and the confusion is worth clearing up before anything else.
A price band limits how far one security can move in a session. When people say a stock “hit upper circuit”, this is what they mean. It applies per stock, every day, and is routine — dozens of securities touch their bands on an ordinary session.
A market-wide circuit breaker halts trading across the entire market when a benchmark index moves far enough. It applies to everything at once, it has been triggered only a handful of times in Indian history, and it is what this chapter is about.
The trigger
The market-wide circuit breaker is a SEBI-mandated mechanism applying simultaneously to the equity and equity derivatives segments of both exchanges.
It is triggered at three thresholds — 10%, 15% and 20% — of movement in either the BSE SENSEX or the NIFTY 50, whichever breaches the level first. The calculation is against the previous day’s closing level of that index.
Two features of the trigger design are worth noting.
It is symmetric. The breaker fires on a move of that magnitude in either direction. In practice every Indian trigger to date has been on a fall, but the rule does not distinguish.
It fires on whichever index gets there first. The two benchmarks do not move identically, so the breach is determined by whichever crosses the threshold earlier. The halt then applies market-wide regardless of which index triggered it.
The index levels corresponding to each percentage are computed by the exchanges and published in advance — recalculated at the start of each quarter and held constant through it, so that intraday levels are known rather than derived on the fly.
The halt durations
This is the part that is genuinely complicated, because the consequence of a breach depends on when in the session it happens. The logic is that a halt is more useful earlier in the day, when there is time remaining for orderly resumption, and that a late-session breach is better handled by closing.
| Trigger | Time of breach | Halt duration |
|---|---|---|
| 10% | Before 1:00 pm | 45 minutes |
| 10% | 1:00 pm to 2:30 pm | 15 minutes |
| 10% | After 2:30 pm | No halt — trading continues |
| 15% | Before 1:00 pm | 1 hour 45 minutes |
| 15% | 1:00 pm to 2:00 pm | 45 minutes |
| 15% | After 2:00 pm | Trading halted for the rest of the day |
| 20% | Any time | Trading halted for the rest of the day |
A 10% breach after 2:30 pm produces no halt at all. That is deliberate: with under an hour left, suspending trade would leave participants unable to adjust positions before the close, which is a worse outcome than letting the session finish.
The thresholds are also sequential within a day. A market that falls 10% in the morning, halts, resumes and then falls to 15% triggers the 15% breaker with its own duration. The 10% breaker does not fire twice.
What happens when trading resumes
A halt does not simply end with continuous trading restarting where it stopped. Resumption runs through a 15-minute pre-open call auction session:
- Orders are collected but not matched for most of the window
- A single equilibrium price is discovered for each security
- All trades at resumption execute at that discovered price
- Continuous trading then restarts
The reason is that the halt exists to let information disseminate and participants reassess. Restarting straight into continuous matching would hand an advantage to whoever happened to have an order resting closest to the front of the book. A call auction gives everyone the same reopening price.
Our page on NSE pre-open market timings and rules covers how the call auction mechanism itself works, since it is the same machinery used at the start of a normal day.
When it has actually fired
Market-wide circuit breakers are rare in India — the mechanism has operated only a small number of times since its introduction in 2001.
The most recent occasions were in March 2020, during the pandemic selloff, when the 10% threshold was breached and trading halted for 45 minutes on more than one session. Before that, triggers occurred in 2008 during the global financial crisis and in 2009 following an election result.
The rarity is the point. A mechanism that fired often would be a mechanism set too tight — it would interrupt ordinary volatility rather than genuine disorder. Three triggers in two decades suggests thresholds calibrated to events rather than to noise.
How this differs from a stock’s price band
Worth setting out side by side, because the two get conflated constantly.
| Market-wide circuit breaker | Per-security price band | |
|---|---|---|
| Scope | Entire market, both exchanges | One security |
| Trigger | SENSEX or NIFTY 50 moves 10/15/20% | That stock moves to its own limit |
| Effect | Trading halts everywhere | That stock can still trade, but only at or inside the limit |
| Frequency | A handful of times in two decades | Dozens of securities daily |
| Set by | SEBI, uniform | Exchange, per security, revised periodically |
| Band sizes | 10%, 15%, 20% | Commonly 2%, 5%, 10%, 20%, or none |
The crucial practical difference: a price band does not stop trading. A stock at its upper circuit can still be bought and sold — just not above that price. Buyers queue and sellers are scarce, so it often looks frozen, but the market is open. A market-wide breaker genuinely suspends matching.
Securities in the derivatives segment carry no daily price band at all, which surprises people — the band mechanism is replaced there by other controls. Our pages on upper circuit stocks and lower circuit stocks identify which securities closed at a limit on the latest session and state the band each one carries.
The third mechanism: dynamic price bands
There is a further control that is neither of the above, and it operates far more often than either.
For securities in the derivatives segment and index futures — which have no fixed daily band — the exchange applies a dynamic price band, initially around 10%. When orders begin accumulating at the limit, the exchange flexes the band outward in increments after a cooling-off period, rather than holding it fixed.
This is why an index future can move more than 10% in a session without any market-wide breaker firing: the band moved, in steps, under a defined procedure.
What a halt does not do
Three things a circuit breaker is sometimes assumed to achieve:
It does not change the price. When trading resumes, the market reopens wherever the call auction discovers. A halt provides time, not support. Markets have resumed lower after halts more often than higher.
It does not stop a fall. The 2020 triggers were followed by further declines in subsequent sessions. The mechanism interrupts a single day’s disorder; it has no view on the trend.
It does not protect positions. A halt freezes your ability to act alongside everyone else’s. If you wanted out, the halt prevented it. Leveraged positions in particular are exposed during a halt — the position stays open, the margin requirement stays live, and you cannot trade out of it.
That last point is the one worth internalising. A circuit breaker is a market-integrity measure designed to let information propagate and settlement systems cope. It is not an investor protection, and it is not on your side.
The honest summary
The market-wide circuit breaker fires at 10%, 15% or 20% on SENSEX or NIFTY 50, whichever breaches first, measured against the previous close. The halt length depends on the time of day, ranging from no halt at all for a 10% breach after 2:30 pm to a full-day closure for anything at 20%. Resumption is always through a 15-minute call auction rather than straight into continuous trading.
It has fired only a handful of times in two decades, and when people say a stock “hit circuit” they are almost always talking about its price band instead — a different mechanism, operating per security, that limits price rather than suspending trade.
Clock-time thresholds in the halt table depend on the session schedule, and Indian market timings have been revised during 2026. Our market timings page carries the current schedule.
Related reading
- Upper circuit stocks — securities that closed at their upper price band on the latest session.
- Lower circuit stocks today — the same at the lower limit.
- NSE pre-open market timings and rules — the call auction used at resumption.
- Market timings — the current session schedule.
- ASM and GSM list — the surveillance framework, a fourth and separate set of restrictions.