Trailing stop loss explained with rupee examples

Trailing stop loss explained in plain rupees: how a stop fills on a gap, how a trail moves for longs and shorts, and how to size a trade from your stop.

26 September 2026 7 min read #basics #options #risk

A trailing stop loss is a stop that follows the price when it moves in your favour, and never moves back. If you bought, it sits a fixed percentage below the last price and only ever rises. If you sold, it sits above the price and only ever falls.

Every trading course tells you to use a stop-loss. Few explain what happens when it fires, or how a trail decides where to move. And almost nobody warns you that a stop that suits a stock can be a near-certain loss on an option. Those details decide whether your stop protects you or just charges you brokerage on the way out.

What is a stop loss, and what price do you get?

A stop-loss is a price level. When the market reaches it, your position closes at whatever price the market is trading at in that moment.

Most of the time that's your stop price, or a tick or two past it. On a news day, though, prices jump.

Say you're long a Nifty option at ₹180 with a stop at ₹160. The premium (the option's price) goes from ₹165 straight to ₹148 between one trade and the next. Your position closes at ₹148. You lose ₹32 a unit, not the ₹20 you planned.

That's how a stop-loss market order works at a real broker, and it's how stops work on our desk. Every tick is checked. When a tick is at or through your level, the position closes at that tick's price.

A simulator that fills your stop exactly at the level, whatever the market did, teaches you a stop caps your loss. It only does that in a smooth market, which is when you needed it least. So plan your loss at the stop, and expect worse on a gap.

Where does the stop go on a long or a short?

If you bought (a long position), the stop goes below your entry and the target above it. If you sold first (a short position), it flips. The stop goes above your entry, because a short loses money when the price rises, and the target goes below.

Options make this confusing, because "bearish" and "short" aren't the same thing.

Buying a put is bearish, but you bought something. You're long the put, so its stop goes below the price you paid.
Selling a call is also bearish, and this one is a short. Its stop goes above the premium you collected.

On our order ticket, if you flip the side of an order, any stop and target you'd typed get cleared. That way a level meant for one side can't quietly end up on the other.

How does a trailing stop loss move?

You give a trailing stop a distance. Here it's a percentage of the last price. The stop sits that far away and only ever tightens.

For a long position with a 10% trail:

stop = the higher of (the current stop, last price × 0.90)

Say you buy one lot of an option at ₹200, 75 units, with a 10% trail and no fixed stop.

What happens	Premium	Stop
You buy	₹200	₹180
Premium rises	₹240	₹216
Premium dips (10% below is ₹207, but the stop never loosens)	₹230	₹216
Premium falls to the stop, stop fires	₹216	exit

You exit near ₹216 against an entry of ₹200. That's ₹16 × 75 = ₹1,200 gross, before charges. With a fixed ₹180 stop and no trail, the trade would still be open, and you'd still be wondering if it comes back.

How does a trailing stop work on a short?

For a short, everything flips. The trail sits above the price and follows it down:

stop = the lower of (the current stop, last price × 1.10)

Sell an option at ₹200 with a 10% trail. The stop starts at ₹220. The premium decays to ₹150, and the stop follows it down to ₹165. A bounce to ₹165 closes the trade at ₹35 a unit in profit against your ₹200 entry, before charges.

Check that your tool actually does this. Trailing logic written only for longs does nothing at all on a short, and it won't tell you. Here it trails both ways.

You can also set a fixed stop and a trail together. The trail takes over only once it's tighter than the fixed level, so your stop is always whichever protects you more.

Why is a 2% trailing stop on an option a coin toss?

On a stock, a 2% trail is tight but reasonable. A large-cap share rarely moves 2% in a few minutes without a reason.

An at-the-money index option can move 10 to 20% in fifteen minutes on an ordinary day. Its price is leveraged exposure to the index, plus a volatility part that moves on its own. We broke that down in the index went nowhere and your option lost money.

A 2% trail on a ₹200 premium is ₹4. That's less than a normal minute of noise, so it fires on the first wobble, whether or not your idea was right.

We learnt this the hard way. Early on, our desk pre-filled the order ticket with a stop half a percent below the price and a target one percent above. On an option premium that's under one tick of movement. Both fired within seconds, at levels nobody had chosen. Now the ticket pre-fills no stop and no target. Your stop should be your own decision.

A better way to pick the distance:

Watch how the premium moves. How far does it usually go against you in 10 or 15 minutes on a quiet day? Your stop needs to sit outside that.
Put the stop where your idea is wrong, not where the loss starts to feel bad. If your reason was "Nifty holds above the day's pivot", the stop goes where the option would be if Nifty broke it.
Then size the trade so that loss is okay. That's next.

How do you size a trade from your stop loss?

Decide the loss first, then the quantity.

Say you're willing to lose ₹2,000 on one trade, 2% of a ₹1,00,000 account. You want to buy an option at ₹180, and the stop that makes sense is ₹150. That's ₹30 a unit of risk.

₹2,000 ÷ ₹30 = about 66 units

But the lot size (units in one contract) is 75. So even one lot is more risk than you planned: ₹30 × 75 = ₹2,250 to the stop, before charges and before any gap.

You can accept ₹2,250, find a trade with a closer logical stop, or skip it. Don't move the stop closer until the maths works. Then it sits where your calculator wants it, not where the market says you're wrong.

Our order ticket shows risk to stop in rupees as you type the level. You see that number before the order exists, not after the stop has fired.

What stop loss habits should you practise on paper?

Put the stop in before the order goes in. A "mental stop" usually means no stop.
Never widen a stop once the trade is live. Tightening is fine, and a trail does it for you. Widening means a bigger loss you never agreed to.
Review the stops that fired. On the trade history page, filter a month and look at your exits. If most stopped-out trades came back within a few minutes, your stop was inside the noise.

A stop can't turn a bad trade good. It keeps the bad ones small, so the good ones can pay for them. Holding overnight? Read intraday vs delivery charges for what a gap at the open does to a stop.

Quick answers

What is a trailing stop loss?

A stop that follows the price in your favour by a set percentage and never moves back. For a long it only rises; for a short it only falls.

Will my stop loss always fill at my stop price?

No. It closes at the price of the tick that reached or crossed your level. If the price gaps past it, you get the worse price.

What trailing stop percentage should I use on options?

There's no single number. Keep the trail outside the premium's normal movement over 10 to 15 minutes. A 2% trail is usually far too tight.

Does a trailing stop work for short positions?

It should. On a short, the trail sits above the price and follows it down. Here it works both ways.

All figures are illustrative and none of this is investment advice. Check how your own broker handles stop orders.

Try it on a simulator first.

₹1,00,000, real NSE prices, and every charge in this post applied to every trade.

Start with ₹1,00,000