What are Circuit Limits?
Circuit limits (or price bands) are daily price movement limits set by stock exchanges for individual stocks. If a stock's price reaches the upper circuit limit, it cannot trade higher for the rest of that session. If it hits the lower circuit, it cannot trade lower. These limits prevent extreme intraday volatility and manipulation.
Three Circuit Bands for Individual Stocks
SEBI and the exchanges classify stocks into three circuit bands:
- 20% band: Price can move ±20% from previous close. Applied to most large, liquid, mainboard stocks.
- 10% band: Applied to mid-sized stocks with moderate liquidity.
- 5% band: Applied to illiquid, volatile, or surveillance-listed stocks.
Some SME IPOs on listing day have a 5% circuit. Some newly listed stocks start with 20% and may be reduced if trading patterns look suspicious.
What Happens When a Stock Hits Upper Circuit?
When a stock reaches its upper circuit price, only buy orders can be placed — no sell orders are accepted. Trading "freezes" at that price. The stock shows up as "UC" (Upper Circuit). Since there are no sellers, no trades execute at or above that price. Buyers who placed orders are stuck waiting.
Similarly, at lower circuit, only sell orders are accepted. No buyers. The stock shows "LC" (Lower Circuit).
Index-Level Circuit Breakers
When Nifty 50 or Sensex move sharply in a single day, market-wide circuit breakers kick in:
- 10% move: Trading halted for 45 minutes (if before 1 PM). 15 minutes (if between 1 PM and 2:30 PM). No halt if after 2:30 PM.
- 15% move: Halted for 1 hour 45 minutes (if before 1 PM). 45 minutes (after 1 PM). No halt after 2 PM.
- 20% move: Market closed for the entire day, regardless of time.
Index-level circuit breakers have been triggered only a handful of times in Indian market history — including the 1992 Harshad Mehta scam, 2004 UPA election result shock, and the 2008 global financial crisis.
Dynamic vs Static Circuits
- Static circuit: Fixed % from the previous day's closing price. The most common type.
- Dynamic circuit: Band moves intraday based on the VWAP (Volume-Weighted Average Price). Prevents sharp intraday spikes even within the static band.
NSE uses dynamic price bands for most actively traded stocks to provide real-time volatility control alongside static overnight bands.
ASM and GSM — Enhanced Surveillance
SEBI maintains two surveillance frameworks for suspicious stocks:
- ASM (Additional Surveillance Measure): Stocks showing unusual price movement, high volatility, or low delivery %. Places stock under 5% circuit, enhanced margin requirements, and closer monitoring. ASM list published on NSE/BSE websites.
- GSM (Graded Surveillance Measure): Stricter — 5% circuit + 100% margin requirement + periodic trade restrictions. Companies that don't comply with disclosure norms or show suspicious trading are placed here.
Stocks in ASM/GSM Stage II-VI are very high risk. Treat them as warning signs, not opportunities.
Practical Implications for Investors
- Stuck in upper circuit: You can place buy orders but cannot sell. If you hold the stock and want to exit, you must wait for a day when sellers emerge.
- Lower circuit trap: If a stock is in lower circuit for multiple days, you cannot sell — causing panic and forced holding. This is why small-cap investors must have stop losses.
- SME IPO listing: Many SME IPOs hit upper circuit on listing day, then lower circuit on day 2 — a classic sign of manipulation. Avoid chasing these.