A circuit breaker in the stock market is a mechanism that sets a price band within which a stock can be traded on a given day. Circuit breakers operate automatically by halting trading when global exchange values reach predetermined levels. This band includes a lower limit (lower circuit) and an upper limit (upper circuit).
Why is a Circuit Breaker Needed?
Stock prices often fluctuate due to market sentiments, influenced by positive or negative news. Circuit breakers are set up to prevent extreme price movements, protecting investors from sudden, unexpected changes. They also help reduce price manipulation to some extent.
The Securities and Exchange Board of India (SEBI) has defined various circuit levels: 2%, 5%, 10%, and 20%. These levels are based on the stock's closing price from the previous day.
Example:
If XYZ stock closed at ₹100 yesterday and has a 10% circuit limit, today it can only be traded between ₹90 (lower limit) and ₹110 (upper limit). If the stock reaches either limit, trading is halted.
How Circuit Breakers Work
In the trade world, a circuit breaker serves the same purpose as it does in residential electrical circuits. It engages and cuts the circuit when it senses an overload. Circuit breakers are emergency safeguards in the trading industry put in place by stock markets to temporarily or permanently halt trading activity when market prices decline drastically.
Individual Stocks:
If the price hits the upper or lower limit, trading in that particular stock is halted.
Market Indices:
A 10%, 15%, or 20% change triggers a market-wide halt.
Upper and Lower Circuit Limits
The limits prevent excessive speculation and volatility. Depending on the stock category, a stock can shift by 5%, 10%, or a maximum of 20% during a trading day.
Example of Upper Circuit and Lower Circuit
Let's say XYZ stock closed at ₹100 yesterday. If it has a 10% circuit limit:
- Upper Circuit: The upper limit would be ₹110 (10% above ₹100). If the stock price reaches ₹110, trading is halted because it has hit the upper circuit. This indicates strong buying interest, and the price can't go higher for the rest of the day.
- Lower Circuit: The lower limit would be ₹90 (10% below ₹100). If the stock price drops to ₹90, trading is halted because it has hit the lower circuit. This indicates strong selling pressure, and the price can't go lower for the rest of the day.
Market-Wide Circuit Breakers
Time-Based Rules:
- Before 1 PM: A 15% movement halts the market for 1 hour and 45 minutes, followed by a 15-minute pre-opening session.
- Between 1 PM and 2 PM: A 15% movement halts the market for 45 minutes, followed by a 15-minute pre-opening session.
- After 2 PM: A 15% movement halts the market for the rest of the day.
- At Any Time: A 20% movement halts the market for the entire day.
Summary Table of Circuit Breaker Durations
Conclusion
Circuit breakers play a important role in stabilizing the stock market by preventing excessive volatility and protecting investors from sudden, significant price changes.