Stock market foundationsModule 4, lesson 18 of 29
Stop-loss and stop-limit orders
How a stop-loss order waits for a trigger price, how stop-loss limit and stop-loss market orders differ, and why a stop cannot guarantee your exit price.
In this lesson
- Explain what a trigger price is and when a stop-loss order becomes a live order.
- Tell a stop-loss limit order from a stop-loss market order and predict how each behaves.
- Explain why a price gap can leave a stop-loss limit order unfilled, or fill a stop-loss market order far below the trigger.
- Describe the choices involved in setting a stop and the limits of what it protects against.
Builds on
- Market orders and limit ordersA stop-loss order turns into a market order or a limit order once it is triggered.
On this page
In simple terms
A stop-loss order is an instruction that waits until the price reaches a level you choose, called the trigger price, and only then becomes a live order in the market. Investors usually use it to limit a loss: "if this share falls to ₹460, sell it." It can also be used to buy: "if this share rises to ₹600, buy it."
Until the trigger is reached, the order is not visible in the market and cannot trade. Once it is triggered, it behaves like one of the ordinary orders from the market and limit orders lesson.
How a stop-loss order is triggered
On the exchanges' trading systems, stop-loss orders are kept in a separate stop-loss book until their condition is met. A sell stop-loss order is triggered when the last traded price reaches or falls below the trigger price. A buy stop-loss order is triggered when the last traded price reaches or rises above the trigger price. Once triggered, the order is released into the normal order book, time-stamped at the moment of triggering, and matched like any other order.
There are two kinds, and the difference matters most when prices move fast:
| How they differ | Stop-loss limit (SL) | Stop-loss market (SL-M) |
|---|---|---|
| What you set | A trigger price and a limit price | A trigger price only |
| After the trigger | Becomes a limit order at your limit price | Becomes a market order |
| Price you get | Your limit or better, if it fills | The best price available, which can be far from the trigger |
| Risk | It may not fill at all | It may fill at a much worse price |
For a sell stop-loss limit order, the limit price is set at or below the trigger, for example a trigger of ₹460 and a limit of ₹455, so the order has some room to fill after it is triggered. Brokers' apps label these orders differently and do not all offer stop-loss market orders in every segment, so check the order types in the app you use.
Worked example
Worked example: Two ways a stop can play out
You bought 100 shares of a made-up company, Sagar Textiles, at ₹500. You decide you will not accept a loss of more than about ₹4,000, so you place a stop-loss sell order: trigger ₹460, limit ₹455.
A gradual fall. The price slides through the day from ₹480 to ₹470, ₹465 and then trades at ₹460. The order is triggered and enters the book as a limit sell at ₹455. Buyers are bidding around ₹459 to ₹457, so it fills at about ₹457.
| Planned loss at the trigger: (500 − 460) × 100 | ₹4,000 |
|---|---|
| Actual loss, filled at about ₹457: (500 − 457) × 100 | ₹4,300 |
A gap. The company announces bad results after the market closes. Next morning the share opens at ₹420 and stays there. Your order is triggered at the open, but as a limit sell at ₹455 it cannot fill, because nobody is buying at ₹455. You still own the shares.
| If it had been a stop-loss market order, filled near ₹420: (500 − 420) × 100 | ₹8,000 |
|---|
In the gap, the limit version protected your price but did not get you out; the market version got you out at twice the planned loss.
Choosing where to put a stop
There is no correct distance for a stop, only trade-offs:
- Too close, and ordinary day-to-day movement will trigger it, selling shares you meant to keep.
- Too far, and the loss you accept when it triggers may be larger than you can afford.
- Volatile shares move more each day, so a stop at the same percentage distance is triggered more often than on a steady share.
Some investors decide the most they are willing to lose first and then work out how many shares to buy, a method covered later under position sizing. Others do not use stop orders at all for long-term holdings, and review the investment itself when the price falls. Both are choices to make in advance, not in the middle of a fall.
Things a stop cannot do
- Beat a gap. Prices can jump past your trigger between sessions or on sudden news, as in the example.
- Find buyers who are not there. When a share hits its lower price band, there may be only sellers and no trades at all.
- Stay active for ever. Many orders last only for the trading day unless your broker offers a longer-lasting version. Check how long yours stays valid.
Why it matters
A stop-loss order is one of the few tools that can carry out a decision while you are not watching the screen, and it makes you decide your exit before emotions take over. But many beginners treat it as a guaranteed floor under their losses. Understanding exactly what happens after the trigger, and when it fails, is what turns it from a false comfort into a useful tool.
Limitations
- The trigger is based on the last traded price, which a single small trade can move in an illiquid share.
- Order types, their names and how long they stay valid differ between brokers and segments.
- A stop deals with price, not with the reason the price fell. It does not tell you whether the investment is still sound.
Common mistakes
- Believing the trigger price is the sale price. It is only the price that starts the order.
- Setting the limit equal to the trigger. If the price drops through the trigger quickly, there may be no room for the order to fill.
- Placing stops so tight that normal moves trigger them, then buying back higher.
- Forgetting the order expired. A day order placed yesterday is no longer protecting you today.
Try it yourself
- Pick a share and look at its highest and lowest prices on each of the last ten trading days. How far did it typically move within a day?
- Decide where you would put a stop if you owned 50 shares and did not want to lose more than ₹2,000. Would ordinary daily moves have triggered it?
- Open your broker's order screen without placing an order, and note which stop-loss order types it offers and how long each stays valid.
Key takeaways
- A stop-loss order waits outside the market until the last traded price reaches a trigger price you set. Only then does it become a live order.
- Once triggered, a stop-loss limit order (SL) becomes a limit order, and a stop-loss market order (SL-M) becomes a market order.
- A stop does not guarantee your exit price. If the price jumps past the trigger, a limit version may not fill at all and a market version may fill far below the trigger.
- A stop placed too close to the current price is likely to be triggered by ordinary price movement.
- A stop limits a planned loss only when it fills; it is a tool for carrying out a plan, not a guarantee.
Check your understanding
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Terms used in this lesson
- Stop-loss order
- An order that waits until the price reaches a trigger you set, then becomes a live limit order (SL) or market order (SL-M).
- Trigger price
- The price at which a waiting stop-loss order is activated and sent into the market as a live order.
- Price gap
- A jump between one trade and the next with no trades in between, often between one day's close and the next day's open.
- Limit order
- An order to buy at or below a set price, or sell at or above it, which controls the price but may not be filled.
- Market order
- An order to buy or sell immediately at the best prices currently available, which guarantees speed but not price.
References
- Trading system (order books, order types and stop-loss orders), National Stock Exchange of India. How stop-loss orders are held and triggered on NSE's trading system.
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This lesson is general education, not investment advice. Examples use made-up or clearly dated figures to explain ideas; they are not recommendations. Read the disclaimer.