Option Buying in Indian Markets: Lots, Costs and Real P&L

What Option Buying Actually Means

Option buying is paying a fixed, upfront amount called the premium for the right, but not the obligation, to take a position in an underlying asset at a fixed price. When you buy a call you are paying for the right to be long. When you buy a put you are paying for the right to be short. You can walk away from that right and lose only the premium. That is the single most important feature for a buyer, your downside is capped at what you paid, while your upside on a call is theoretically open ended.

The seller, also called the writer, takes the opposite side. The writer collects your premium and accepts unlimited or large risk in exchange. This is why SEBI requires writers to post margin while buyers only pay premium. As a buyer you are renting a directional bet with a known cost. The catch is that you are fighting time and volatility, not just direction, which is why most beginners who only buy options struggle until they understand premium decay.

On Indian exchanges the most actively traded options are on indices: Nifty 50 and Sensex with weekly expiries, and Bank Nifty, FinNifty and others on monthly expiries after SEBI consolidated weekly expiries to one per exchange in late 2024. Stock options exist too but carry far less liquidity than index options, so the spreads are wider and the costs are higher for a buyer.

The Lot Size Rule You Cannot Ignore

In Indian derivatives you do not buy a single unit. You buy a lot, and the premium quoted on the screen is always per share. To get the rupee amount you pay or the rupee profit you make, you multiply the per share number by the lot size. Getting this wrong is the most common reason a new trader thinks an option is cheap when the real cash outlay is much larger.

A Fully Worked Nifty Call Example With Real Numbers

All figures below are illustrative and used to show the arithmetic. They are not a prediction and not a promise of returns. Say Nifty is trading near 24,000 and you expect a bounce this week. You buy one lot of the 24,000 weekly call at a premium of Rs 120 per share. Nifty lot size is 65, so your cash outlay and maximum possible loss is 120 times 75 equals Rs 9,000 for that one lot, plus a small amount of charges.

Now suppose the view works and by Wednesday Nifty has moved up, and that same 24,000 call is now quoting Rs 180. You square off (you do not exercise, because these are European and settle only at expiry). Your gross profit is the premium gain per share times the lot: (180 minus 120) times 65 equals 60 times 65 equals Rs 3,900 gross on a Rs 7,800 outlay. That is the headline number, but it is not what hits your bank account.

Now the opposite. Suppose instead Nifty drifts sideways and falls, and by expiry it closes at 23,950, below your 24,000 strike. The call is out of the money and expires worthless. You lose the entire premium: 120 times 75 equals Rs 9,000. There is no margin call and nothing more to pay, but the whole premium is gone. This is the buyer's bargain, capped loss in exchange for the steady drag of time decay.

What The Profit Looks Like After Costs

On the winning trade above, the Rs 4,500 gross is reduced by transaction costs. For an option buyer the main charges are STT (securities transaction tax, charged at 0.1 percent on the premium value of the sell leg for options), exchange transaction charges, SEBI fees, GST at 18 percent on brokerage plus exchange charges, stamp duty on the buy side and brokerage itself. A typical discount broker charges a flat fee such as Rs 20 per executed order.

So the real net is roughly Rs 4,425, not Rs 4,500. On a single lot the cost drag is small, but for a trader doing many lots or scalping in and out several times a day, these charges compound and can quietly turn a marginally profitable strategy into a losing one. Always size your edge against your full cost stack, not the gross.

Why European Exercise Changes How You Trade

This is the most important correction to a myth many Indian beginners carry over from American textbooks. Every option listed on NSE and BSE today is European style. Index options (Nifty, Bank Nifty, FinNifty, Sensex) have always been European, and Indian single stock options were converted from American to European style years ago. European style means the option can be exercised only on expiry day, never before.

In practice this means you almost never exercise at all. If your option is in profit before expiry, you simply sell it back in the market to lock the gain, the same way you bought it. You only let it go to expiry if you want intrinsic value settled. Index options are cash settled on the final settlement price, while stock options are physically settled, meaning if your in the money stock option is open at expiry you must take or give delivery of the shares, which needs full cash or stock, a frequent and expensive surprise for unwary traders.

• European style: exercise only on expiry day, so you square off in the market to take profits early.
• Index options are cash settled against the closing settlement value, no shares change hands.
• Stock options are physically settled, an in the money stock option left open at expiry triggers delivery obligations.
• There is no early assignment risk for buyers in India because nothing can be exercised before expiry.

Time Decay Is The Buyer's Biggest Enemy

Every option loses a little value each day purely because there is less time left for the underlying to move. This is theta, or time decay. For a buyer it is a daily headwind. On weekly Nifty and Sensex options the decay is brutal in the last two or three days, especially for out of the money strikes, because the chance of finishing in the money shrinks fast. An option can lose half its value in a flat market simply because Wednesday became Thursday.

This is why directional accuracy is not enough. You must be right on direction, magnitude and timing all together. If Nifty is going to move but takes a week to do it and you bought a two day option, you can be correct on direction and still lose your whole premium. Many disciplined buyers prefer slightly in the money or at the money options and avoid holding cheap far out of the money lottery tickets into expiry day.

The Greeks A Buyer Should Watch

The option Greeks measure how the premium reacts to different forces. You do not need to compute them by hand, your broker terminal shows them, but you should understand what each one tells you before you take a position.

A common trap is buying calls or puts right before an event such as a budget or RBI policy, when volatility and therefore premiums are already inflated. Even if the index moves your way, a collapse in India VIX after the event (a vega crush) can leave you flat or losing. Buying when volatility is cheap and selling when it spikes is far kinder to a buyer than the reverse.

Common Mistakes Indian Option Buyers Make

• Treating the per share premium as the total risk and forgetting to multiply by the lot size of 65, 30, 60 or 20.
• Buying deep out of the money weekly options because they look cheap, then watching theta erase them in two days.
• Holding an in the money stock option into expiry and getting hit with physical delivery obligations.
• Buying options just before a big event when implied volatility is at its peak, then suffering a vega crush.
• Ignoring brokerage, STT and GST when scalping many lots, so a small per trade edge is eaten by costs.
• Forgetting that F&O profits are taxed as business income at slab rates, not the gentler capital gains rates.

Each of these is avoidable with a simple pre trade checklist: confirm the lot size and total outlay, check days to expiry against your expected move, check whether the instrument is cash or physically settled, and glance at India VIX before paying up for premium.

How Option Buying Profits Are Taxed In India

Profit or loss from buying and selling options is treated as non speculative business income under Indian tax rules, not as capital gains. This means it is added to your other income and taxed at your applicable slab rate. The 20 percent short term and 12.5 percent long term capital gains rates that apply to equity delivery do not apply to F&O. For reference, equity STCG is 20 percent and LTCG is 12.5 percent above Rs 1.25 lakh, but those are for shares held in your demat, not for option trading.

Because it is business income, you can set off F&O losses against other business income and carry forward losses, and you can claim genuine expenses such as brokerage, internet and software. If your turnover crosses the threshold, a tax audit may be required. The STT you pay on each option sell leg is a transaction cost, not income tax, and is reflected in the cost table above. Keep clean records of every trade, since the income tax department expects F&O to be reported as a business.

Is Option Buying Right For You

Option buying suits a trader who has a clear, time bound directional view and wants strictly limited risk. The defined loss is genuinely useful, you can know to the rupee what a bad day costs you before you enter. But the same structure that caps your loss also means you start every trade behind, because you have paid premium that decays. Buyers who survive treat each trade as a small, disciplined bet, size by lots not by gut, and exit by selling in the market rather than waiting on expiry mechanics.

Beginners should start with a single lot of a liquid index option, paper trade or trade tiny first, and track every trade in a journal so the true effect of costs and time decay becomes visible. Nothing here is a recommendation to trade or a promise of profit. Options are a high risk product, and a large majority of individual F&O traders in India report net losses, as SEBI's own studies have shown.

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.