Reverse Calendar Spread: Buying the Near Month to Bet on a Big Move

A reverse calendar spread is the calendar spread turned inside out. Instead of selling the near-month option and buying the far month, you buy the near month and sell the far month, both at the same strike on the same underlying. The trade usually brings in a small net credit, and it does best when the market makes a large move, in either direction, before the near-month option expires.

That sounds attractive on paper. A credit up front, and you get paid for a big move without picking a side. But the structure has a sting in its tail that many traders only notice after their first one goes wrong. This guide walks through how the trade is built, why it behaves the way it does, three worked scenarios with round hypothetical numbers, and the risks we think matter most for an Indian F&O trader.

What a reverse calendar spread actually is

Investopedia’s explainer on the reverse calendar spread defines it simply: buy a short-term option and sell a long-term option on the same security, with the same strike price. It is the opposite of a conventional calendar spread, and it also goes by the names reverse horizontal spread and reverse time spread.

“Horizontal” is the key word. In a vertical spread, both legs share an expiry and differ by strike. In a horizontal spread, both legs share a strike and differ by expiry. A diagonal spread changes both. So in a reverse calendar spread the only thing separating your two options is time.

Both legs must be the same type. You can build it with two calls or with two puts, but not one of each. A typical call version on an index looks like this:

• Buy one near-month at-the-money call.
• Sell one next-month call at the same strike.

The longer-dated option carries more time value, so it costs more than the near-month one. You collect more on the sale than you pay on the purchase, and the trade opens as a net credit.

Why the trade wants a big move

To see why, it helps to recall what the regular calendar spread is betting on. Investopedia’s page on the calendar spread explains that a normal calendar profits from time decay when the underlying stays fairly stable, because an option’s rate of time decay (its theta) speeds up as expiry gets closer. The near-month option you sold melts faster than the far-month option you own. We covered that version in detail in our post on the calendar spread options strategy.

Flip the legs and the logic flips too. Now you own the option that is decaying fastest and you are short the one that decays slowly. If the market sits still, the near-month option you bought bleeds value quicker than the far-month option you sold, and the spread moves against you.

What rescues the trade is a sharp move away from the strike. Here is the mechanism, in plain terms:

• When the underlying runs far above or far below the strike, both options lose most of their time value. A deep in-the-money option trades close to its intrinsic value, and a far out-of-the-money option trades close to zero.
• The far-month option had more time value to begin with, so it has more to lose. You are short that option, so its loss of time value is your gain.
• Your best case is that both options end up worth almost the same, the gap between them shrinks towards nothing, and you keep most of the credit you collected at the start.

The calendar spread page adds a second route to profit: a spike in implied volatility can lift option values even without a big price move. That point needs care with the reverse version, and we come back to it below, because volatility can just as easily hurt you here.

A normal calendar spread wants the market to go to sleep. The reverse calendar wants it to wake up, quickly, and travel a long way from the strike.

Worked example: a reverse calendar spread on the Nifty

Every number in this section is hypothetical and rounded so the arithmetic is easy to follow. These are not real market prices, and the lot size is an assumption, not the exchange’s current lot size.

The setup. Say the Nifty is at 24,000. You:

• Buy the near-month 24,000 call for ₹180.
• Sell the next-month 24,000 call for ₹320.

Net credit: ₹320 minus ₹180, which is ₹140 per unit. On an assumed lot of 100 units, that is ₹14,000 received when the trade opens.

Now let us look at three outcomes on the day the near-month call expires. In each case the next-month call still has roughly a month to run, so it still has some time value left. The values we assign to it are, again, made up for illustration.

Scenario 1: the Nifty rallies to 25,500

The near-month call expires 1,500 points in the money, so it is worth ₹1,500. The next-month call is now deep in the money and trades close to intrinsic value. Assume it is ₹1,540, which is ₹1,500 of intrinsic value plus ₹40 of time value.

Profit and loss per unit: the ₹140 credit, plus ₹1,500 from the expiring call, minus ₹1,540 to buy back the call you sold. That comes to +₹100, or ₹10,000 on our assumed lot.

Scenario 2: the Nifty falls to 23,000

The near-month call expires worthless. The next-month call is now 1,000 points out of the money with a month left. Assume it is worth only ₹25.

Profit and loss per unit: ₹140 credit, plus nothing from the expired call, minus ₹25 to buy back the short call. That is +₹115, or ₹11,500 on the lot. A big fall worked out as well as a big rally. That is the whole appeal.

Scenario 3: the Nifty ends right at 24,000

This is the bad case. The near-month call expires at the money and is worth nothing. The next-month call is also at the money, still has a month of time value, and assume it is worth ₹230.

Profit and loss per unit: ₹140 credit, minus ₹230 to buy back the short call. That is −₹90, or a ₹9,000 loss on the lot. If implied volatility has gone up in the meantime and that call is worth ₹300 instead, the loss widens to ₹160 per unit, or ₹16,000.

Look at the shape of those numbers. The two winning scenarios made ₹100 and ₹115, both below the ₹140 credit. That is not a coincidence. Even after a huge move, the far-month option keeps a little time value, so the most you can realistically keep is something less than the credit you started with. The upside is capped. The downside, as the next section shows, is not.

The best a reverse calendar can do is hand back most of the credit you collected. The worst case is an open-ended short option once your near-month leg expires.

The risk nobody should skip

The near-month call you own is the only thing protecting your short far-month call. Once that near-month option expires, the protection is gone. If you do nothing, you are left holding a naked short call, which has no ceiling on its potential loss if the market keeps rising. With puts, a naked short put loses heavily if the market keeps falling.

So in practice, most traders treat the reverse calendar spread as a trade that ends on or before the near-month expiry. Either both legs are closed together, or the short leg is bought back the moment the long leg expires. Holding the short option alone after that point turns a defined-looking spread into a very different, much riskier position.

There is also the margin question. Investopedia notes that the reverse calendar spread is not commonly used by individual investors in stock or index options because of the margin requirements, and that it is more common among institutional investors. That makes sense once you see the structure: you are short a longer-dated option, and the hedge on it expires first. Before placing the trade, run both legs through your broker’s margin calculator so the blocked amount does not surprise you.

Volatility cuts both ways

Investopedia’s calendar spread page points out that longer-term options are more sensitive to changes in implied volatility, which is to say they have a higher vega. In a regular calendar, you own that high-vega far-month option, so a rise in implied volatility helps you.

In a reverse calendar spread you are short the far-month option. So, all else equal, a broad rise in implied volatility tends to work against you, and a fall tends to help. The reverse calendar page itself says the strategy might be used by traders expecting decreased volatility. The calendar spread page, meanwhile, says a reverse calendar can aim to profit from a spike in implied volatility. Both can be true in different situations, because the two expiries rarely trade at the same implied volatility, and a volatility jump that lands mostly on the near month can lift your long leg more than your short one.

Our honest reading is this: do not put on a reverse calendar spread purely as a volatility bet unless you understand how near-month and far-month implied volatility usually move relative to each other on that underlying. The cleaner reason to use it is an expected big price move before the near expiry. Our explainer on the vega options Greek and the piece on implied volatility vs historical volatility are useful background here.

Reverse calendar spread vs long straddle

If the goal is to profit from a big move without picking a direction, the obvious comparison is the long straddle, where you buy a call and a put at the same strike. The two trades are built very differently.

• Cash flow. A long straddle costs money up front. A reverse calendar usually brings money in.
• Upside. A straddle’s profit grows the further the market moves. A reverse calendar’s profit is capped at less than its opening credit.
• Downside. A straddle buyer can lose at most the premium paid. A reverse calendar’s loss depends on how much the far-month option is worth when you close it, and it becomes open-ended if the short leg is left alone after the near expiry.
• Time decay. Both lose money when the market goes nowhere. The straddle bleeds on both legs. The reverse calendar bleeds because the near-month leg it owns decays faster than the far-month leg it sold.

In simple terms, the straddle pays you for being right about a big move and charges you up front. The reverse calendar pays you a little up front and asks you to accept a capped reward with a less predictable loss. Neither is better in every case. They suit different risk appetites.

When a trader might consider it

Some situations where a large move before the near-month expiry looks more likely than usual:

• A scheduled event that lands before the near expiry, such as a policy decision or a company’s quarterly results, when you expect the reaction to be large.
• A stock or index that has been coiling in a tight range and looks ready to break out, though the breakout direction is unclear.
• A period when near-month options look cheap relative to the next month, which lowers the cost of the long leg.

None of these guarantee a move. Markets often shrug off events that everyone expected to be big. That is why the position size matters more than the setup.

A short checklist before you place one

1. Use the same underlying, the same strike and the same option type on both legs. Check that only the expiry differs.
2. Note the net credit and work out, with your own numbers, what the far-month option might still be worth at the near expiry if the market does not move.
3. Check the margin your broker will block, and keep spare funds in case it rises.
4. Decide in advance that you will close or cover the short leg on or before the near-month expiry. Write it down.
5. Look at liquidity in the far-month strike. Wide bid-ask spreads in the next-month contract can eat a large part of a small credit.
6. Size the trade so the bad scenario, where the market sits at the strike, is a loss you can take calmly.

The reverse calendar spread is a niche tool. It earns a small, capped reward when the market moves hard, and it can hurt when the market goes quiet or when the short leg is left uncovered. If you are still getting comfortable with how option prices respond to time and volatility, our guide to options trading for beginners in India and the post on theta decay in options trading are better places to start.

Disclaimer: This article is for education only and is not investment advice. All prices, lot sizes and outcomes in the worked examples are hypothetical. Options trading carries a high risk of loss. Please consult a SEBI-registered investment adviser before making any trading decision.