Cost of Carry in Indian Markets: Formula, Worked Nifty Example and Tax

What Cost of Carry Actually Means

Cost of carry is the net cost of holding the underlying asset from today until the day a futures contract expires. When you buy a futures contract instead of buying the shares outright, the seller is effectively holding the asset for you. They tie up capital, lose the interest that money could have earned, and in exchange they collect any dividends on the way. The futures price has to compensate for this, so it usually trades a little above the spot price.

For physical commodities the carry includes real out of pocket items such as warehouse rent, insurance and spoilage. For financial assets like Nifty, Bank Nifty or a single stock such as Reliance, there is no storage. The carry is almost entirely the financing cost, which is the risk free interest you give up by parking money in the position, reduced by any dividends the underlying pays before expiry. This is why cost of carry for index futures is sometimes just called the basis when expressed in points.

The single most useful idea is this: the fair futures price equals the spot price plus the cost of carry. If you can compute the carry, you can compute what the futures should be worth, and then judge whether the live market price is rich or cheap.

The Cost of Carry Formula Used in Indian Markets

The textbook fair value formula for an index or stock future is Futures = Spot x e^(r x t) minus D, where r is the annual risk free rate as a decimal, t is the time to expiry expressed as a fraction of a year, e is the base of natural logarithms (about 2.71828), and D is the rupee value of dividends expected before expiry. Many Indian desks use the simpler discrete version Futures = Spot x (1 + r x t) minus D, which gives almost the same answer for short one month contracts.

The two versions differ only because one assumes continuous compounding and the other simple interest. Over a 30 day Nifty contract the gap is a fraction of a point, so traders often quote whichever is handy. What matters is being consistent and using a realistic rate. In India the right r is roughly the short term money market rate, often proxied by the 91 day Treasury bill yield or the MIBOR, not the RBI repo rate by itself.

Fully Worked Nifty Example With the Actual Futures Price

Take a concrete, illustrative case. Suppose Nifty 50 spot is at 17,800, the relevant short term risk free rate is 6.75 percent per year, the contract has 30 days to its monthly expiry, and no index dividends are expected in that window. The Nifty lot size is 65. We want the fair futures price, not a vague statement that it is calculated accordingly.

First convert time to a fraction of a year: t = 30 divided by 365 = 0.08219 years. Then the carry multiplier using simple interest is (1 + r x t) = 1 + (0.0675 x 0.08219) = 1 + 0.005548 = 1.005548. Multiply by spot: Fair futures = 17,800 x 1.005548 = 17,898.76, which rounds to about 17,899. The cost of carry in points is 17,899 minus 17,800, which is roughly 99 index points, or about 0.55 percent of spot for the month.

Using the continuous version gives almost the same figure: e^(0.0675 x 0.08219) = e^0.005548 = 1.005563, so Fair futures = 17,800 x 1.005563 = 17,899.02, essentially the same 17,899. So the honest answer to the example is a clear number: the fair Nifty future is about 17,899, a carry of about 99 points, not an unspecified small cost.

Now add a dividend. If index constituents were expected to pay dividends worth about 25 Nifty points before expiry, subtract them: 17,899 minus 25 = 17,874. Dividends lower the fair future because the futures buyer does not receive them, so they are compensated with a lower entry price. This is exactly why heavy dividend seasons compress the basis on dividend rich stocks.

What the Carry Means in Rupees and After Costs

Translate the points into money. One Nifty lot is 65 units, so a 99 point carry on one lot equals 99 x 65 = Rs 6,435 of theoretical carry built into the price of a single contract for the month. If you held five lots, the embedded carry would be about Rs 32,175. This is not a fee you pay separately. It is already baked into the quoted futures price, which is why the future trades above spot.

Transaction costs are separate and they matter for anyone trying to trade the basis. On the futures sell leg, Securities Transaction Tax, known as STT, is charged at 0.02 percent of the sell side turnover. On a one lot Nifty future at 17,899, the contract value is 17,899 x 75, which is about Rs 13,42,425, so STT on the sell leg is roughly Rs 268. Add exchange transaction charges, GST on brokerage and charges, SEBI turnover fees and stamp duty on the buy side, and the all in round trip cost on one index futures lot typically lands in the low hundreds of rupees, illustrative and broker dependent.

Cash and Carry Arbitrage: When the Future Is Too Rich

Suppose in the example above the actual Nifty future is quoted at 17,940 while the fair value is 17,899. The future is 41 points rich. An arbitrageur can in theory buy the basket in the cash market and sell the future, locking in the gap. At expiry the future converges to spot, and the 41 point spread minus the real cost of carry is the gross arbitrage. This is called cash and carry arbitrage, and it is the mechanism that keeps futures from drifting too far from fair value.

On a single stock it is cleaner to picture. Say Reliance spot is 2,800 and its one month future, at the same 6.75 percent and 30 days with no dividend, has a fair value of about 2,800 x 1.005548 = 2,815.5. The Reliance lot size on NSE varies, so check the current contract, but the logic is identical. If the future trades at 2,830, the 14.5 point richness above fair value is the raw edge an arbitrage desk would target, before brokerage, STT and the practical difficulty of borrowing or short selling the stock.

• Buy the underlying in the cash segment, which costs you financing for the holding period, that is your carry.
• Sell the equivalent futures contract at the richer price.
• Hold to expiry, where the future settles to spot and the basis collapses to zero.
• Pocket the difference between the original basis and your actual cost of carry, minus all transaction costs and taxes.

Contango and Backwardation in Plain Terms

When the futures price sits above spot, the market is in contango, the normal state for index futures because positive carry pushes the future higher. Our 17,899 future over a 17,800 spot is a textbook contango of 99 points. When the future sits below spot, the market is in backwardation. For an index this is unusual and often signals heavy dividend expectations, aggressive short selling, or a sudden spike in borrow demand.

Watching whether the basis is widening or narrowing through the expiry cycle tells you about positioning. A basis that collapses sharply before expiry, sometimes turning negative, can reflect unwinding of long futures positions or rollover pressure. Reading these shifts alongside open interest gives a fuller picture than price alone.

Expiry Mechanics That Change the Carry

Cost of carry shrinks as expiry approaches because t shrinks toward zero. A 99 point carry on a fresh 30 day contract is mathematically pulled toward zero as the contract ages, and on expiry day the future and spot converge. This decay is mechanical and predictable, which is why the basis is largest at the start of a series and smallest near settlement.

Indian index derivatives have moved to a structured weekly and monthly expiry calendar. Monthly futures and options on the NSE expire on the last Tuesday of the month, or the prior trading day if that is a holiday, while weekly index options expire on their designated weekday. SEBI has tightened the number of weekly expiries to curb churn, so always confirm the current expiry day for the specific index on the NSE contract page. The shorter the time to your chosen expiry, the smaller the carry baked into the price.

How Interest Rates and Dividends Move the Carry

Two levers drive the carry. The first is the interest rate. A higher r means a higher financing cost, a higher fair future and a wider contango. If the RBI tightens policy and short term rates climb from 6.75 percent to 7.50 percent, redo the 30 day Nifty math: 17,800 x (1 + 0.075 x 0.08219) = 17,800 x 1.006164 = 17,909.7, so the fair future rises from about 17,899 to about 17,910, a carry of roughly 110 points instead of 99.

The second lever is dividends. Because the futures holder does not collect dividends, expected payouts are subtracted from the fair value. On dividend heavy single stocks the future can trade at a discount to spot right around the ex dividend date, a perfectly rational mini backwardation rather than a bearish signal. Misreading a dividend driven discount as a sell signal is a classic beginner error.

• Higher short term interest rates widen the carry and lift the fair futures price.
• Lower rates compress the carry and pull the future closer to spot.
• Expected dividends reduce the fair futures price by their rupee value in points.
• Time decay shrinks the carry steadily as expiry nears, reaching zero at settlement.

Taxes on Futures Profits in India

This is where Indian rules differ sharply from equity delivery. Profits from futures and options trading are treated as business income, not capital gains. They are added to your total income and taxed at your applicable slab rate, whether you trade Nifty, Bank Nifty or single stock futures. The familiar STCG and LTCG rules do not apply to F and O at all.

For comparison, if you instead bought and sold the actual shares in the cash segment, the capital gains rules would apply: short term capital gains at 20 percent and long term capital gains at 12.5 percent on amounts above Rs 1.25 lakh in a financial year. But the moment you express the view through a futures contract, the gain becomes business income at slab rates. STT on futures is levied on the sell side at 0.02 percent of turnover, and is a cost, not a tax credit. Because F and O is business income, related trading expenses can generally be claimed, and turnover thresholds may trigger tax audit requirements. Confirm specifics with a qualified tax professional before filing.

Common Mistakes Traders Make With Cost of Carry

The biggest mistake is ignoring carry entirely and treating the spot to futures gap as a free signal. A future trading 99 points over Nifty is not bullish on its own. It is simply fair value carry. Reading normal contango as a directional view leads to bad trades. The second mistake is using the wrong interest rate, such as a long bond yield, which inflates the fair value and makes the live future look artificially cheap.

A third trap is forgetting dividends on single stock futures, then panicking when the future dips below spot around an ex dividend date. A fourth is treating arbitrage edges as risk free when transaction costs, STT, the difficulty of short selling cash stock, and margin funding can erase a thin basis. Always net out the real costs before calling something an arbitrage.

• Treating normal contango as a bullish or bearish signal.
• Plugging a long term bond yield into a one month carry calculation.
• Ignoring dividends on stock futures and misreading the resulting discount.
• Assuming the basis is free profit and forgetting STT, brokerage and slippage.

Using Cost of Carry in a Real Trading Routine

In practice you do not need to recompute carry by hand all day. Compute the fair value once at the start of a series for your chosen index, then track how the live basis moves around it. A basis that is persistently far above fair value points to crowded long futures positioning, while a basis stuck below fair value flags dividend effects or short pressure. This arbitrage aware lens is more useful than staring at price alone, and it feeds naturally into your trading strategies and rollover decisions.

For rollovers near expiry, the carry tells you the fair spread between the near month and next month contract. If the spread you are charged to roll is much wider than the model carry, you are overpaying. Logging your fair value, the live basis and your actual roll cost in your trading journal over several expiries builds an intuition no formula alone can give you.

Sources and Further Reading

For authoritative data and further reading on this topic, refer to NSE India, Zerodha Varsity and Investopedia. Always confirm current rules, rates and contract specifications on the official source before you trade.

Sources and Further Reading

For authoritative data and further reading on this topic, refer to NSE India, Zerodha Varsity and Investopedia. Always confirm current rules, rates and contract specifications on the official source before you trade.