Three things that sound like one
A price band sets the allowed trading range for a particular security. A market-wide circuit breaker responds to a large move in a benchmark index and can pause trading across markets. A trading halt describes the interruption itself; it can also follow an operational problem or a security-specific suspension.
People often call all of these a circuit. That shortcut hides the question that matters: is one share restricted, or has the wider market stopped?
At the boundary
Hypothetical only: Bharat Foods has a ₹500 reference close and a fixed 5% daily band. Its real story has not changed.
The displayed band is a rule for this example, not a claim about Bharat Foods' actual exchange classification.
What the band does not promise
A fixed band is normally set using a reference such as the previous close. NSE uses different bands for different securities, including 2%, 5%, 10% and 20%; the applicable exchange file matters. Corporate actions can require adjustments.
Cash shares with derivatives available generally use dynamic operating ranges, rather than the same fixed daily band. Those ranges can be expanded under exchange rules. That does not mean every order at every price is accepted.
In the hypothetical lower-circuit queue, changing a sell order to market does not manufacture demand. Nor does a stop-loss order guarantee an exit: reaching its trigger only activates an order, which still needs execution.
The next trading day's range can be based on a lower reference close. A daily boundary is therefore not a maximum loss over several days. Several downward moves can accumulate.
In the hypothetical 5% band, Bharat Foods is at ₹475 with sellers waiting and no buy orders. You send a market sell. What follows?
When the whole market pauses
NSE's index-based circuit framework uses moves of 10%, 15% and 20%, upwards or downwards, in the Nifty 50 or BSE Sensex, whichever triggers first. It coordinates interruptions in equity and equity-derivatives markets.
The duration depends on the threshold and the time. For example, a 10% trigger before 13:00 gives a 45-minute halt, followed by a 15-minute pre-open. A 10% trigger at or after 14:30 does not cause a halt under that rule. A 20% trigger ends trading for the rest of the day.
That is why 'the market hit a circuit' is incomplete information. Identify the index move, time and exchange notice. A security suspended for a compliance issue is a different case again; a market-wide reopening does not automatically lift that suspension.