Expiry, settlement and assignment

Every derivative contract has a death date. Most beginner education covers how to enter positions and almost nothing about how they end.

That gap is expensive, because a meaningful share of avoidable F&O losses happen not from a bad trade but from a misunderstood expiry.

What settlement means#

At expiry the contract is closed out and obligations are settled. There are two ways this happens in Indian markets, and which one applies to you matters enormously.

Index derivatives — Nifty, Bank Nifty and the rest — are cash settled. Nobody delivers an index. The difference between your position and the final settlement price is credited or debited, and it is over.

Stock derivatives are physically settled. If you hold a stock futures position or an in-the-money stock option to expiry, actual shares change hands. You either deliver them or take delivery of them.

Settlement price is not the closing price#

A reasonable assumption is that a contract settles at the underlying's last traded price. It does not.

Index derivatives settle at a weighted average of the underlying over the final stretch of the session, not the closing tick. The precise methodology is defined by the exchange.

The practical consequence: a sharp move in the last minutes moves the settlement price far less than it moves the visible last price. A position that looks like it finished in the money by a whisker may settle otherwise. Do not plan a trade around a settlement value you have inferred from the chart.

Moneyness at expiry#

At expiry, all time value is gone. An option is worth exactly its intrinsic value:

• In the money (ITM) — has intrinsic value, settles for that amount
• At the money (ATM) — strike essentially equal to spot, worth approximately nothing
• Out of the money (OTM) — expires worthless, premium entirely lost

That last line is the one to sit with. An out-of-the-money option does not decline gracefully. On expiry day it goes to zero, and the entire premium is gone.

Most weekly options bought by retail traders expire worthless. Not because those traders were unusually unlucky — because most options are out of the money at expiry, which is exactly what their prices implied all along.

Assignment: the seller's side#

If you sell an option, you have an obligation. When the buyer exercises, you are assigned — you must honour your side.

Three things to know:

Indian index options are European style. They can only be exercised at expiry, not before. This removes early-assignment risk entirely for index options, which is a genuine simplification.

Assignment is automatic for in-the-money options. You do not get a decision. If your sold option finishes in the money, it settles against you.

On stock options, assignment means delivery. Sell a stock call that finishes in the money and you may be required to deliver shares you do not own. This is how a modest premium sale becomes a serious problem.

Squaring off versus letting it expire#

You have two ways out of a position:

Square off — trade out of it before expiry. You realise the current market price, and the position is genuinely closed.

Let it expire — do nothing and allow settlement to occur.

For index options, letting an OTM option expire worthless is usually fine, and saves you the exit cost on a near-zero position. Letting an ITM option expire is usually also fine, since it settles in cash.

For stock options, letting anything in the money expire is where the delivery problem starts. When in doubt, square off.

Why expiry day behaves differently#

As expiry approaches, the mechanics of options change character:

Time value evaporates non-linearly. The last day removes what remains of it, and the removal accelerates through the session.

Gamma spikes near the strike. Small moves in spot produce large swings in an option's delta, so positions become far more sensitive than they were the day before.

Premiums look cheap and are not. A ₹5 weekly option on expiry morning is cheap in rupees and expensive in probability. Most of them go to zero.

Expiry day is a distinct discipline with its own lessons later in this track. If you are inside your first few months, the most useful policy is to be flat before it — not because expiry cannot be traded, but because it is a poor place to learn.

Check yourself

0 of 4 answered

1. 1.You hold one in-the-money stock option lot into expiry, having paid ₹4,000 in premium. What is the main risk?

   Losing the ₹4,000 premiumPhysical settlement — you may need to fund delivery of the full contract value in sharesThe exchange will cancel the contractNothing; it settles in cash like index options

2. 2.Indian index options are European style. What does that mean for a seller?

   They can be assigned at any time before expiryThey can only be exercised at expiry, so there is no early assignment riskThey settle in shares rather than cashThey cannot be sold, only bought

3. 3.Nifty spikes sharply in the final minutes of expiry day. How does this affect settlement?

   Settlement uses the last traded price, so the spike matters fullySettlement uses a weighted average over the final stretch, so the spike matters much lessSettlement is cancelled if the move is too largeSettlement uses the day's high

4. 4.What happens to an out-of-the-money option at expiry?

   It retains some time valueIt is rolled to the next expiry automaticallyIt expires worthless and the entire premium is lostIt settles at the strike price

What to take away

• Index derivatives settle in cash. Stock derivatives settle physically.
• Physical delivery can demand far more capital than the premium you paid. Close stock options before expiry while learning.
• Settlement price is a weighted average, not the closing tick.
• OTM expires worthless — the whole premium, not a portion.
• Indian index options are European, so no early assignment.
• Write the expiry date down with every trade.