Pin Risk in Options: What Happens When Expiry Lands on Your Strike

Most options traders worry about the stock running away from them. Pin risk in options is the opposite problem: the stock does almost nothing, and on expiry day it settles right on top of your strike. A rupee above or below decides whether you walk away clean or end up with a delivery obligation worth several lakh. For stock options in India, where open in-the-money positions are settled by actual delivery of shares, that last-hour coin toss deserves more respect than it usually gets.

This piece explains what pin risk is, why it bites harder on NSE stock options than many people assume, and how we would think about it as an option writer and as an option buyer. The numbers in the worked example are hypothetical, chosen only to make the arithmetic easy to follow.

What pin risk in options actually means

Investopedia defines pin risk as the uncertainty traders face when the underlying closes very close to the option’s strike price at expiration. Nobody is sure whether the option will be exercised, so nobody is sure what position they will be left holding.

Think about it from the writer’s chair. If the option finishes even slightly out of the money, the seller keeps the full premium and the trade is over. If it finishes even slightly in the money, the seller can be assigned, and a short call turns into a short position in the stock while a short put turns into a long one. The premium was small. The position that replaces it is not.

Investopedia also points to a second, murkier issue it calls pinning: as expiry nears, buyers sitting on large open interest at a strike may try to push the price to a level that helps them. It notes that pinning tends to show up at strikes with heavy open interest in both calls and puts. Whether or not anyone is actively pushing, the effect for a writer is the same. The stock hovers, the clock runs out, and the outcome hangs on the last few ticks.

Why the Indian version is about delivery, not just a weekend gap

In the US example Investopedia uses, the pain usually comes from an unexpected stock position carried over a weekend and the gap that can follow on Monday. Here the bigger shock is the settlement itself.

A SEBI board memorandum from October 2022 lays out how this works. SEBI’s April 2018 circular mandated physical settlement of stock derivatives in a phased manner. On expiry, single-stock futures and options are settled by creating funds and delivery obligations from open positions. In-the-money option contracts that are exercised and assigned are settled physically, and out-of-the-money contracts expire worthless.

Zerodha’s October 2019 policy note on compulsory delivery contracts says that from the October 2019 expiry, all stock F&O contracts moved to compulsory physical delivery. So a short call that ends in the money does not just cost you the intrinsic value. You have to hand over shares. A long put that ends in the money means you have to deliver shares too. If those shares are not in your demat account, Zerodha’s note says the result is short delivery, with auction penalties from the exchange charged to the account.

We have covered the plumbing of this in more detail in our guide to physical settlement of stock F&O. For pin risk, the point is simple: in Indian stock options, a two-rupee miss at the close can turn a tidy premium trade into a full-sized share delivery.

The premium you collected is a few thousand rupees. The delivery obligation that can replace it is the full contract value. Pin risk lives in the gap between those two numbers.

Close-to-money contracts and the “Do Not Exercise” twist

India’s rules add a wrinkle that sits exactly in pin-risk territory. Exchanges define a band of close to money (CTM) contracts. Per the SEBI memo and Zerodha’s note, for calls these are the three in-the-money strikes immediately below the final settlement price, and for puts the three in-the-money strikes immediately above it.

Zerodha’s note uses Wipro to make it concrete. If the Wipro contract settles at 243 on expiry day, the 230, 235 and 240 calls are CTM, and so are the 245, 250 and 255 puts.

The history of the facility attached to these contracts is a bit of a back-and-forth, and it matters for anyone holding positions near the strike:

• The SEBI memo says exchanges introduced a “Do Not Exercise” (DNE) facility in August 2017 so holders of CTM options could choose not to exercise. The original reason was that STT was then charged on the settlement price, which could leave some barely in-the-money holders with a negative payoff.
• From September 2019, STT moved to being levied on the option’s intrinsic value, which removed that negative-payoff concern, and the memo says the DNE facility was discontinued from October 2021.
• Livemint reported in April 2022 that NSE was reintroducing DNE for stock options from 28 April 2022, after some traders who could not close positions on expiry day had been forced into physical settlement. The SEBI memo describes that restoration as an interim measure while it worked on a structural fix.

Rules in this area have changed more than once, so check your broker’s current policy and the latest exchange circulars before relying on DNE. What the history does show is that regulators themselves saw the CTM band as a risk zone. The SEBI memo spells out the scenario plainly: without DNE, an option that was out of the money suddenly turning in the money on expiry day forces the holder to bring in cash or securities for physical settlement, and a large enough position could become a systemic problem.

For a writer, the CTM band adds one more unknown. If holders can choose not to exercise near-the-money contracts, you cannot be sure how much of your short position will actually end up as delivery.

A worked example: one short call, three endings

Let us take a hypothetical stock, call it Company Q, with a hypothetical lot size of 400 shares. You sold one lot of the 1,500 call at ₹8 earlier in the month and are still holding it on expiry day.

• Premium collected: 400 × ₹8 = ₹3,200
• Contract value at the strike: 400 × ₹1,500 = ₹6,00,000

At 3 pm the stock is drifting between ₹1,497 and ₹1,503. You now have to decide what to do with less than half an hour left.

Ending A: it settles at ₹1,497

The call is out of the money. It expires worthless, you keep ₹3,200, and there is no delivery. This is the ending everyone plans for.

Ending B: it settles at ₹1,502

The call is ₹2 in the money, inside the CTM band. If it is exercised, you must deliver 400 shares at ₹1,500. Those shares are worth 400 × ₹1,502 = ₹6,00,800 at the settlement price, so the option itself costs you ₹2 × 400 = ₹800. Against the ₹3,200 premium, you are still ₹2,400 ahead on paper.

That sounds fine until you remember the other half. You need 400 shares in your demat account. If you do not have them, you are in short-delivery territory, and the auction penalty is not something you can calculate in advance. A trade that “made money” can end with a bill nobody modelled.

Ending C: you hedge, and the hedge is the problem

Say that at 3:15 pm, worried about Ending B, you buy 400 shares at ₹1,499 so you can deliver if assigned. Then the stock slips and settles at ₹1,497. The call expires worthless and you keep the ₹3,200, but you now own 400 shares you did not want:

• Mark-to-market on the hedge at settlement: (₹1,497 − ₹1,499) × 400 = −₹800
• Unhedged exposure carried overnight: 400 × ₹1,497 = ₹5,98,800
• If the stock opens 2% lower the next morning, that is a further hit of about ₹11,976

Add it up and a trade that started with ₹3,200 of premium is now roughly ₹9,576 in the red. This is the trap Investopedia describes: near the strike, almost any hedge you pick eats into the profit, and the wrong one creates a fresh risk of its own.

Near the strike, there is no hedge that is right in every ending. The only clean answer is to not be holding the position when the music stops.

The buyer’s side is not risk-free either

Option buyers are taught that their loss is limited to the premium. With physically settled stock options, that is only true if the option expires out of the money.

If you hold a long call that ends in the money, you must take delivery and pay the full contract value. If you hold a long put that ends in the money, you must deliver the shares. Zerodha’s note describes a physical delivery margin of 50% of the contract value on in-the-money long options under its policy, and says its margin on stock futures and short options rises on expiry day to 40% of contract value or exchange SPAN plus exposure, whichever is higher. On our hypothetical Company Q lot, 40% of ₹6,00,000 would be ₹2,40,000. Brokers set their own policies here, and they change, so treat these as one broker’s published numbers rather than a market rule.

Zerodha’s worked case shows how small the trigger can be. A long Wipro 240 call with the stock settling at 243 has an intrinsic value of 3 × 3,200 (the lot size in its example) = ₹9,600. That modest gain comes with a delivery obligation on the whole lot.

How traders manage pin risk

None of this needs fancy tools. It needs discipline about time.

1. Close stock option positions before the final session if the stock is anywhere near your strike. The extra rupee or two of premium you might squeeze out by holding is rarely worth the delivery lottery. Liquidity in physically settled contracts can thin out close to expiry, which Zerodha’s note also flags, so earlier is better than the last ten minutes.
2. Know your broker’s expiry-week rules. Some brokers raise margins, block fresh long positions near expiry or square off positions that fall short. Zerodha’s note, for example, says losses from its risk team squaring off under-margined positions are borne by the client.
3. Check whether your legs net off. Zerodha’s note says opposing positions in the same expiry, such as a long call and a short call in a bull call spread that both end in the money, net off and need no delivery. A spread where one leg ends in the money and the other does not will not net, which is exactly what can happen when the price settles between your two strikes.
4. Size for the delivery, not the premium. If you could not comfortably fund or deliver the full lot, you should not be holding that position into the close on expiry day.
5. Watch where open interest is stacked. Heavy open interest in both calls and puts at one strike is where Investopedia says pinning tends to show up. Our explainer on max pain theory and options expiry covers how traders read that clustering, and why it is a tendency rather than a law.

The short version

Pin risk is what happens when the market refuses to make a decision for you. In Indian stock options, the cost of that indecision is not just a few rupees of intrinsic value. It can be a full share delivery you did not plan for, a hedge that becomes a fresh open position, or a penalty for shares you never had.

If you are still getting comfortable with how options work in India, start with our options trading for beginners guide before writing stock options into expiry. The rule we would keep is a boring one: when the price is sitting on your strike near the end of expiry day, square off and let someone else take the coin toss.

Disclaimer: This article is for educational purposes only and is not investment advice. The Company Q figures are hypothetical. Exchange and broker rules on physical settlement, margins and the Do Not Exercise facility change from time to time, so check the current circulars and your broker’s policy, and consult a SEBI-registered adviser before trading derivatives.