On Monday 29 Jun 2026 the June Nifty future settled at 23,972.90. The July future settled at 24,037.70. Anyone long June who wanted to stay long after the June contract expired on Tuesday had to sell June and buy July. The gap between the two, 64.80 points, came to Rs 4,212 a lot. By that close about two thirds of all Nifty futures open interest already sat in later months. A future ends on a set date. A view or a hedge that outlasts it needs a roll, and a roll is two trades with a price of their own. I treat it as a trade with a cost, not as housekeeping. This lesson covers when traders roll, why they do, and what it costs. Every figure comes from NSE end of day files and is dated, not live.
3By the end you can
- Describe a roll for a long and for a short, and say when most of it happens.
- Work out what a roll costs: the spread between months and the charges on two trades.
- Explain why a high rollover share says where positions sit and not which way they point.
The idea, plainly
Every Nifty future expires on the last Tuesday of its month, or the trading day before when that Tuesday is a holiday, and NSE lists three at a time: the near month, the next month and the far month. A trader who wants the same exposure after expiry has to close the old contract and open the next one. That is a rollover. A long rolls by selling the near month and buying the next. A short rolls by buying the near month and selling the next.
Most of the June roll came in the last few sessions before expiry
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Who rolls, and why? An investor hedging a share portfolio for longer than a month. A trader whose view has not changed. A fund running cash and carry, which must keep its futures leg alive to match its shares. None of them is sending a signal. Each is keeping a position, not making a new one.
When? Mostly late. The rollover figure is the share of all Nifty futures open interest that already sits in later months. Here it is for the June 2026 expiry, session by session.
The share stays modest for the first week and then climbs steeply. By two sessions before expiry about half of the open interest had moved on, and by expiry day most of it had.
What a roll costs
Three things. The first is the spread between the two months, the price of one more month of carry, the same carry as in module F08. It is not a fee that anyone keeps. If the cash you did not spend sits in a bill, it earns the interest that the spread is made of. The second is the charges on two trades. The third is slippage, the cost of trading a month that may be thin, which an end of day file cannot show.
A roll is two trades, and the gap between the two prices is what it costs
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A roll does not create a new gain or loss by itself. The old contract's gains and losses have already moved in cash every evening, as module F07 showed, and the new contract starts at the settlement price of the day you open it. What the roll adds is the spread and the charges. The short answer is on the rollover cost question page.
The calendar spread, and a margin note
A calendar spread is a long in one month and a short in another, held as one position. A roll is a calendar spread that closes the old leg as it opens the new one. NSE Clearing treats a calendar spread of index futures more kindly than two separate positions: extreme loss margin is levied on one third of the value of the far month leg, and the spread treatment lasts until the day before expiry. On expiry day the expiring leg falls outside it. Module I02 takes the spread as a trade in itself.
Worked example: rolling one lot on 29 Jun 2026
A trader is long one lot of 65 units of the June future and wants to stay long after Tuesday's expiry. On Monday 29 Jun 2026 the trader sells June at 23,972.90 and buys July at 24,037.70. The price of the roll is the difference, 64.80 points. It was not the same on every date of the month:
| Settlement | Spread, points | One lot |
|---|---|---|
| Wed 10 Jun: June 23,240.10, July 23,344.90 | 104.80 | Rs 6,812.00 |
| Tue 16 Jun: June 24,001.00, July 24,087.90 | 86.90 | Rs 5,648.50 |
| Mon 29 Jun: June 23,972.90, July 24,037.70 | 64.80 | Rs 4,212.00 |
The price of the roll, in points, ended the window well below where it began
| One lot, 29 Jun 2026 | Rupees |
|---|---|
| Spread paid | Rs 4,212.00 |
| STT, 0.05% of the June sale | Rs 779.12 |
| NSE transaction charges, both trades | Rs 57.11 |
| Stamp duty on the July purchase | Rs 31.25 |
| SEBI fee and GST on the exchange charge | Rs 13.40 |
| Statutory charges, total | Rs 880.88 |
Read 3 more paragraphs, 159 words
The spread moves with interest rates and with the dividends expected between the two expiries. A lower spread on a later date is not a reason to roll late: the June position carried its own risk in between.
Now the charges, for the roll on 29 Jun. STT falls on the sale only. Stamp duty falls on the purchase only. The exchange charge and the SEBI fee fall on both legs.
The statutory charges came to Rs 880.88. The spread was about 4.8 times that. Brokerage and slippage come on top, and the roll opens a new contract with its own mark to market from the first evening. The cost calculator below opens on one future bought and sold back. Type the July price into the buy leg and the June price into the sell leg to price this roll at the 2026 rates. How the trades are treated for tax is covered in Learn module 11.2.
The common mistake
The belief: High rollover means the market is bullish.
The reasoning is that traders who roll must expect more upside. Check who rolls. A short rolls too: it buys the near month and sells the next, and it counts in the same percentage as a long. Hedgers and cash and carry funds roll because they must, whatever they think. The measure counts positions that moved house, not which way they point. The chart for June ends at a high share, and the March 2026 window below has the same shape. A high reading on expiry day is the usual state of the last session, not news.
The March 2026 expiry had the same shape in a different month
Key takeaways
- A roll closes the near month and opens the next, so exposure continues.
- Most rolling happens in the last few sessions before expiry.
- The roll's price is the spread between months, which is carry for one more month.
- A roll is two trades, each with charges. STT falls on the sale.
- A fall in near month OI before expiry is mostly rolling, not exit.
- High rollover shows where positions sit. It does not point up or down.
The term this section turns on: Rollover
Before you trade. Derivatives trading carries a high risk of loss. SEBI's study "Profitability of Individual Traders in the Equity Derivatives Segment (FY25 to FY26)" (August 2026) found that 87.7% of individual traders in equity F&O made net losses in FY26, with aggregate net losses of Rs 91,685 crore. Read the SEBI study