Lower Circuit in Indian Markets: Price Bands, SEBI Tiers and 2020 Halts

What a lower circuit actually is

A lower circuit is the maximum percentage a stock or index is allowed to fall in a single trading session before the exchange steps in. It is a price floor for the day. Critically, hitting the lower circuit does not always stop trading in a stock. The price simply cannot print below that floor. What usually happens is that everyone wants to sell and almost nobody wants to buy, so a queue of unmatched sell orders builds up at the lower circuit price and the stock is effectively frozen even though the exchange has not formally halted it.

This is a common point of confusion. For an individual stock, hitting the lower price band means trades can still occur at or above the floor, but practically the stock is stuck. For the whole market, the SEBI index circuit breaker is different: when the Nifty 50 or Sensex falls by a set percentage, the exchange formally halts all equity, F&O and currency derivative trading for a fixed number of minutes. These two mechanisms are often lumped together, but they work under separate rules.

Individual stock price bands on NSE and BSE

Every stock on NSE and BSE is assigned a daily price band. The exchange decides the band based on the stock and adjusts it over time. The standard fixed bands are 2%, 5%, 10% and 20%. A 2% band is usually applied to stocks under surveillance or in the trade-to-trade segment where speculation must be curbed. Lower quality or illiquid stocks often sit in the 5% or 10% band, while most ordinary stocks carry a 20% band.

There is an important exception. Stocks that trade in the Futures and Options (F&O) segment, and stocks that are constituents of indices on which derivatives are available, do not have a fixed daily price band. Instead they have a dynamic price band that starts at 10% and is flexed by the exchange in steps of 5% if the stock keeps hitting the band and order books point to a genuine move. This is why a heavyweight like Reliance or HDFC Bank can fall more than 10% in a single day, while a small-cap in the 5% band locks at exactly minus 5%.

The SEBI market-wide index circuit breaker: the real tiers

This is the rule most articles get wrong, so here are the correct figures. SEBI mandates an index-based market-wide circuit breaker with three tiers: 10%, 15% and 20%. The trigger is calculated on the Nifty 50 or the BSE Sensex, whichever is breached first. The percentage move is measured against the previous day closing level of the index. When a tier is hit, the exchange halts trading across the entire equity cash market, the equity derivatives market and the currency derivatives market at the same time.

The length of the halt depends on both the tier and the time of day the level is breached. A 10% fall early in the day causes a longer halt than the same fall in the afternoon, because there is less time left to find a fair price. After a halt ends there is a pre-open call auction session of 15 minutes before normal trading resumes, which lets buyers and sellers re-discover a price without panic order matching. A 20% breach at any time of day ends trading for the rest of the session.

March 2020: what really happened and the actual halt times

The COVID-19 crash gives the clearest real example. On 13 March 2020, the Nifty 50 and Sensex fell roughly 10% within minutes of the open. The lower circuit was breached at around 9:20 AM and the entire market was halted for 45 minutes, in line with the before 1:00 PM rule for a 10% trigger. Trading resumed at about 10:05 AM after the pre-open auction. In a sharp twist, the market then rebounded violently and the Sensex actually closed up several percent that day, a reminder that a lower circuit does not predict the direction of the close.

Then on 23 March 2020, the worst single day of the crash, the indices again hit the 10% lower circuit. The breach happened shortly before 10:00 AM and trading was halted for 45 minutes. This time there was no recovery. After resumption the Sensex fell around 13% and the Nifty fell roughly 13% to close near its lows, one of the largest single-day falls in Indian market history. The 15% tier was approached but not formally triggered in the way the 10% halt was. These two days are the textbook real-world demonstration of the 10% tier and the 45 minute halt rule.

• 13 March 2020: 10% lower circuit near 9:20 AM, 45 minute halt, market then closed sharply higher.
• 23 March 2020: 10% lower circuit near 10:00 AM, 45 minute halt, Sensex and Nifty closed down about 13%.
• Earlier precedent: 22 May 2006 and the 2008 global financial crisis also saw index circuit halts, but the COVID crash is the cleanest modern example.
• In every case the halt applied to cash equities, equity derivatives and currency derivatives together.

A worked example: being trapped long in a lower circuit stock

Numbers below are illustrative and not a prediction. Suppose you buy 500 shares of a mid-cap NSE stock at Rs 200, total outlay Rs 1,00,000. The stock sits in the 5% daily price band. Bad news hits and the stock opens down and quickly locks at its lower circuit. The floor for the day is 5% below the previous close of Rs 200, which is Rs 190. A wall of sell orders forms at Rs 190 and there are no buyers, so you cannot sell at all even though your screen shows a tradable price.

On paper you are down 500 multiplied by Rs 10, which is Rs 5,000, but this is a loss you cannot crystallise. If the stock is in a 5% band and the bad news is serious, it can lock at the lower circuit for several consecutive sessions: Rs 190, then about Rs 180.50, then about Rs 171.50, compounding the trapped loss each day. After five straight lower circuits at 5% your Rs 200 stock would be near Rs 154.81, a paper loss of roughly Rs 22,595 on 500 shares, with you still unable to exit. This is the real danger of low-band illiquid stocks, and it is why position sizing matters more than the entry price.

Why F&O traders hedge with index options during halts

Here is the practical edge. When the cash market index hits a circuit and halts, equity derivatives halt at the same time under the market-wide breaker, but for a single stock locked at its own lower circuit, the index options and futures on Nifty and Bank Nifty often keep trading normally because the index itself has not hit a market-wide tier. A trader who is long a basket of stocks that are sliding can buy Nifty put options to hedge the broad market risk that they cannot hedge by selling their frozen single stocks.

Consider an illustrative hedge. The Nifty lot size is 65. A trader fearing a fall buys one lot of a weekly Nifty 24,000 put at a premium of Rs 120. The cost is 75 multiplied by Rs 120, which is Rs 9,000 plus charges. If the market then drops hard and that put rises to Rs 320 before expiry, the gross gain is 75 multiplied by (Rs 320 minus Rs 120), which is Rs 15,000 before brokerage and STT. STT on options is charged at 0.15% of the sell premium value on sold options, and at 0.15% of intrinsic value on exercised options, and F&O profit is taxed as business income at your slab rate, not as capital gains. The put profit cushions losses on the frozen cash positions you could not sell.

• Nifty weekly and monthly options keep trading even when individual stocks are circuit-locked, as long as the index has not hit a market-wide tier.
• Lot sizes to remember: Nifty 75, Bank Nifty 15, FinNifty 25, Sensex 10.
• F&O gains and losses are business income taxed at your slab, so keep a tax-loss audit trail.
• Options buying caps your loss at the premium paid, which is useful when you cannot place stop losses on a frozen stock.

Lower circuit versus upper circuit

The upper circuit is the mirror image of the lower circuit. It is the ceiling a stock or index can rise to in a single session. At an upper circuit, buyers queue up and there are no sellers, so longs cannot easily add and shorts are trapped. The same fixed bands of 2%, 5%, 10% and 20% apply on the upside, and F&O stocks again use the dynamic band. The market-wide index breaker only triggers on falls, since its purpose is to stop panic crashes, not rallies.

Common mistakes traders make around circuits

The most expensive mistake is placing a market order to sell a stock that is at or near its lower circuit. There is no liquidity at the floor, so your order either does not fill or, if the stock briefly comes off the circuit, fills at a terrible price. A second mistake is assuming a lower circuit means the company is finished. Circuits are often hit on broad market panic, index rebalancing or a temporary news shock, not on fundamentals.

• Do not use market orders into a circuit, use limit orders and accept you may not get filled.
• Do not average down blindly into a stock locked at successive lower circuits, the floor can keep dropping for days.
• Do not confuse a single stock floor with a market-wide halt, only the index tiers freeze the whole market.
• Do check whether the stock is in a 2% or 5% band before trading it, illiquid low-band stocks are the most dangerous to be trapped in.

How circuits fit into your risk management

Circuits are a reminder that a stop loss only works if there is someone to trade with. A stop loss order on a stock that gaps straight to its lower circuit will not protect you, because the price never trades through your stop level in an orderly way. The defence is position sizing and diversification done before the trade, not a stop placed after. Never size a position in a low-band illiquid stock as if you can exit any second, because you often cannot.

For portfolio-level risk, the index circuit breaker is your worst-case scenario. If you are heavily leveraged on the long side and the market hits the 10% tier, your broker may issue a margin call the moment trading resumes. Plan your leverage assuming a 10% gap day is possible, because as March 2020 proved, it is. Sensible risk management assumes liquidity can vanish exactly when you need it most.

Sources and further reading

Circuit limits, price bands and the index breaker rules are revised by the regulator and exchanges from time to time. Always confirm the current band for a specific stock and the live circuit breaker matrix on the official source before you trade. Refer to SEBI, NSE India and BSE India for authoritative figures.

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.