Contents
Definition
A limit order is an instruction to buy or sell a security at a specified price (the limit price) or better. A buy limit order will execute only at the limit price or lower; a sell limit order will execute only at the limit price or higher. If the market price never reaches the limit price during the order's validity, the order expires unexecuted. Limit orders are the backbone of the NSE/BSE central limit order book and are used by retail investors, institutions, and algorithmic market makers alike. Unlike market orders, they provide price certainty at the cost of execution certainty. Source: NSE Capital Market Trading System Specifications v4.x; SEBI Circular MRD/DoP/SE/Cir-07/2005.
How It Works Mechanically
When a limit buy order is entered, it joins the bid side of the order book at the specified price, sorted first by price (highest first) and then by time (earliest first) — price-time priority. If the best ask price drops to or below the limit price, the matching engine executes a trade. Partial fills are possible: if 300 shares are available at your limit price but your order is for 500, you receive 300 shares and the remaining 200 stay queued.
Order validity types on NSE/BSE:
- Day order (DAY): Valid until market close (3:30 PM). Unexecuted portion is automatically cancelled.
- Good Till Cancelled (GTC): Stays open across trading days until filled or manually cancelled (most brokers cap at 30–90 days).
- Immediate or Cancel (IOC): Execute as much as possible immediately; cancel the rest.
- Fill or Kill (FOK): Execute the full quantity immediately or cancel entirely.
- After Market Order (AMO): Entered after 3:30 PM, queued for next-day opening pre-open session.
Limit orders are visible in the market depth window (five levels on each side). Large resting limit orders signal support/resistance levels and are watched by algorithmic traders. Iceberg orders allow institutions to display only a portion of a large limit order to avoid signaling their full size.
Cost Components
- Same explicit costs as market orders: brokerage (₹20 flat or %, capped at 2.5%), STT (0.1%+0.1% delivery; 0.025% intra-day sell), exchange charges, GST, SEBI charges, stamp duty.
- Opportunity cost: If your limit order does not fill and the price moves away, the missed gain or loss is the hidden cost of execution risk.
- No additional charges for cancelling or modifying a limit order (most brokers; check specific broker terms).
Risk / Protection Rules
- Price bands / circuit filters: Limit orders cannot be placed outside the daily price band for a stock. NSE/BSE systems reject limit orders beyond the circuit-filter boundary.
- Freeze quantities: Limit orders above a maximum quantity per order (varies by stock) trigger a pre-trade confirmation requirement — the exchange freezes and reviews these.
- Pre-open equilibrium: Limit orders entered during 9:00–9:08 AM participate in the opening price-discovery auction and may execute at the equilibrium price, which could be better than their limit price.
- GTC risk: A GTC limit order placed at ₹90 before a company announces bad results could execute far below the current price once results are out — participants must actively manage GTC orders.
Worked Example
Investor B wants to buy 200 shares of Asian Paints but only if the price drops to ₹2,800. Asian Paints is currently trading at ₹2,865. She places a limit buy order at ₹2,800, valid for the day. The stock trades between ₹2,830–₹2,870 all day — the order does not execute and is cancelled at 3:30 PM. Next day, weak results trigger a gap-down to ₹2,780. She re-enters the limit order at ₹2,785 and it fills at ₹2,785 (better than her limit). Total brokerage: ₹20 + STT: ₹5,570 × 0.1% = ₹5.57 + exchange charges ~₹1.80 = ~₹27.37 explicit cost on a ₹5,57,000 trade.
Caveats / Common Mistakes
- Setting limit prices too far from market leads to non-execution; too close means you might as well use a market order.
- GTC orders forgotten for weeks can execute at stale prices after corporate actions (splits, bonus) shift the price level. Always audit pending GTC orders after corporate actions.
- Placing limit orders in illiquid stocks at mid-price rarely fills; the bid-ask spread is too wide for mid-price execution.
See Also
- Market order
- Bid-ask spread
- T+1 settlement
- Stock market basics (pillar)
- Brokerage charges comparison India
Primary Source
NSE Capital Market Trading System Specifications; SEBI Circular MRD/DoP/SE/Cir-07/2005
MintByte (ARN-314872 / APMI APRN-01658) provides this glossary for educational purposes only. Nothing here constitutes investment advice, a recommendation to buy or sell any security, or a guarantee of returns. Equity and derivatives trading involves risk of loss. Consult a SEBI-registered adviser before making investment decisions.