Rollover and expiry mechanics

A share can sit in your account forever. A futures contract cannot. It has a death date printed on it — an expiry — after which it simply stops existing. That single fact changes everything about how a futures position behaves, and it is the fact beginners most often forget until it surprises them.

So the question this module answers is deceptively simple: your future is about to expire — what happens, and what are your choices? You have exactly three. Close the position and walk away. Do nothing and let it settle. Or carry your view into the next month by "rolling" it forward. Each path has a cost and a consequence, and none of them is free.

Understanding expiry and rollover is not a technicality. It is the difference between a trader who controls when and how a position ends, and one who gets surprised on expiry afternoon by a settlement they did not choose — or who slowly bleeds their account rolling a view that is taking too long to arrive.

Recall what a future is: a dated promise to settle a price difference on a fixed future day. The whole instrument is built around that date. Without it, there would be nothing to converge to, no moment the carry melts to zero, no anchor. The expiry is the contract.

In India, listed futures come in monthly series — a near month, a next month, and a far month trade at once. Each series has its expiry: the last day it trades, after which it is settled and ceases to exist. Traditionally this has been the last Thursday of the month for stock and Nifty futures, though exchanges have shifted specific weekdays over time; the principle is what matters — a fixed, known, non-negotiable end date for each series.

Because the contract must end, the exchange needs a clean way to close every open position on that day. How it closes depends on what the future is written on. An index future — Nifty, Bank Nifty — uses cash settlement: an index is a number, not a deliverable thing, so the contract settles in money against a final settlement price. Your profit or loss versus your entry is booked in cash, the position closes, and the series is gone. A single-stock future is different: since October 2019 the exchange settles it by physical delivery — a long left open must take delivery of and pay for the full quantity of shares, a short must hand them over, and the expiry-week margins for that obligation are steep. Either way the deadline is real; only the mechanism differs.

This is why "doing nothing" is not neutral. If you hold an open lot into expiry and take no action, it does not roll itself and it does not wait for you. An index lot cash-settles at the final settlement price — whatever that price is; a stock lot drags you into physical delivery you never planned for. Forgetting a position does not pause it; it hands the exchange the decision of where you exit. A dated instrument closes on its date whether or not you are paying attention.

Lay the three choices side by side, because the trap is not knowing which one you are in.

Close it. Before expiry you simply trade out — sell your long, or buy back your short — in the same near-month series. Your profit or loss is realised, margin is released, and you are flat. This is the clean exit: you chose the price and the moment.

Let it settle. You do nothing, and on expiry day the contract settles itself — an index lot cash-settles at the final settlement price; a stock lot instead goes to physical delivery, forcing you to take and pay for (or hand over) the full share quantity. Either way you did not choose the exit — the settlement price is set by the market's close, expiry-day prices can be jumpy, and an unplanned delivery on a stock lot is a nasty surprise on top.

Roll it. You want to keep the same view past this month's death date, so you roll over: close the expiring near-month lot and simultaneously open the same position in the next month's series. Your directional bet continues, but in a fresh contract with a later expiry. This is how a trader "holds" a futures view across months — not by sitting still, but by repeatedly moving the position forward.

Rolling is not free, and its price has a name. The rollover cost is the price difference between the near month you are leaving and the far month you are entering — the spread you pay to move forward. Because the far month usually trades above the near (contango, from the previous module), a long roller typically pays that gap away each time. Add fresh brokerage, exchange charges and taxes on both legs, and re-block margin for the new series, and every roll takes a small, real bite.

Watch the cost of patience in a leveraged instrument. illustrative

You are long one stock-futures lot. Your thesis is sound but slow — you think the stock climbs over the next few months. This month's near future is ₹1,000; next month's trades at ₹1,007 (the usual carry). Expiry arrives and the stock has barely moved. You still believe your view, so you roll: sell the near month around ₹1,000, buy the next month around ₹1,007. That ₹7 gap on 500 shares is ₹3,500 paid away, plus brokerage and taxes on two legs — call the roll ~₹3,800 all-in. Margin re-blocks for the new series.

A month later, same story: the view is right but slow, so you roll again. Another ~₹3,800. And again the month after. Three rolls in, before the stock has done much of anything, you are down roughly ₹11,000–12,000 in pure carrying cost on a single lot — money that has nothing to do with being wrong. You were right. You were just early, and in futures, early is expensive.

Compare the alternative. Had you simply bought the shares in the cash market, you would have paid a one-time brokerage, tied up more money, and then waited — no monthly roll, no bleeding carry, no margin to top up. The slow-but-right view costs almost nothing to hold in cash and bleeds every month in futures. That contrast is the honest cost of using a dated, leveraged instrument to express a patient idea.

Expiry imposes a deadline your thesis did not agree to. The market does not care that your view needs another two months; the contract dies on its date, and you must act or be settled. That forced cadence is where the quiet damage hides.

Rolling is not free, and the cost compounds. Each roll pays the near-far spread plus fresh charges and taxes, and re-blocks margin. Over many months these bites add up into a real drag — a headwind your view must overcome before you make a single rupee. A slow-but-right thesis can be correct and still unprofitable, eaten alive by carrying cost. Every round-trip pays the toll-keeper; run the position enough times and the toll, not the market, decides the outcome.

Expiry-day prices are jumpy. The final settlement price is set at the close, and expiry sessions can lurch as huge volumes settle and roll at once. If you let a position drift into settlement, you accept whatever that jumpy close produces — an exit price you did not choose.

The crowd's deadline is your worst liquidity. Everyone rolls around the same expiry, so spreads can widen exactly when you are forced to trade. The idea that expiry day is "the cheapest day to roll" is often backwards — the deadline concentrates activity and can move the roll cost against you. Chasing a marginally better roll price on the busiest afternoon is picking up small change with a deadline bearing down.

Doing nothing is a decision. Forget the position and it settles anyway. In futures, inaction is not "hold" — it is "let the market's close decide my exit."

Expiry and rollover trip up traders in a few reliable ways.

1. Thinking a futures position rolls itself. It does not. Leave it alone and it settles on expiry — an index lot in cash, a stock lot by forced physical delivery; to keep the view you must actively close and reopen in the next series.

2. Treating rollover as free. Every roll costs the near-far spread plus charges and re-blocked margin. Hold a view across many months and those bites become a serious drag.

3. Assuming expiry day is the best day to roll. The deadline concentrates the crowd, widening spreads and jolting the basis. Timing the roll around expiry can cost more, not less.

4. Forgetting a position into settlement. Doing nothing hands the exchange your exit at a jumpy final price you did not choose. Inaction is a choice with a cost.

5. Using a dated instrument for a patient idea. A right-but-slow thesis bleeds carry every month in futures while it could simply wait in cash. Speed of the view, not just its direction, decides whether futures fit at all.