What Is STT in Options Trading? Rates, the Exercise Trap, and How to Avoid It

Securities Transaction Tax (STT) is a government-mandated tax charged on every buy or sell transaction in Indian equity and derivatives markets. For options traders on NSE and BSE, STT is currently 0.0625% of the premium on the sell side. But the number that ruins accounts is a different figure entirely: when an in-the-money (ITM) options contract is exercised or expires ITM, STT is charged at 0.125% of the full contract's notional value — not the premium — which can wipe out the entire profit from the trade.

This guide explains what STT is, how it's calculated, the expiry-day exercise trap that catches Indian options traders every month, and what traders using platforms outside the NSE/BSE framework pay instead.

What is STT and why does it exist?

Securities Transaction Tax was introduced in India in 2004 as a replacement for the long-term capital gains tax on listed equity. The government applies it directly at the point of transaction — charged by the exchange and collected by the broker, so you never have a choice about paying it.

Unlike brokerage, STT is not negotiable. Every trade on NSE or BSE in equity, futures, or options generates an STT liability regardless of which broker you use, what platform you trade on, or what your account size is.

STT is separate from other transaction costs like exchange transaction charges, GST on brokerage, SEBI turnover charges, stamp duty, and DP charges. On an active F&O account, the combined transaction cost load is significant — and STT is typically the largest single component for futures traders.

Current STT rates on F&O (2026)

The rates below reflect the Budget 2024 increases, which came into effect from October 2024:

| Segment | Charged on | Rate | Who pays | | --- | --- | --- | --- | | Equity futures (sell) | Notional turnover (lot size × price) | 0.02% | Seller | | Options (sell) | Premium received | 0.0625% | Seller | | Options (exercise / expiry ITM) | Notional value of contract | 0.125% | Buyer | | Equity delivery (buy + sell) | Transaction value | 0.1% each way | Both | | Equity intraday (sell only) | Transaction value | 0.025% | Seller |

The most consequential line in this table is the third one: options exercised or expired ITM are taxed at 0.125% on the full notional value, not the premium. This is the trap.

The exercise STT trap: a worked example

Here is the scenario that wipes out profits for Indian options traders every month — often silently.

Suppose you bought a NIFTY call option:

  • Strike: 22,000 CE
  • Lot size: 75
  • Premium paid: ₹50 per unit → total premium = ₹3,750
  • NIFTY at expiry: 22,400 (your option expires deep ITM)
  • Intrinsic value: ₹400 per unit

Your P&L before STT:

Profit = (₹400 − ₹50) × 75 = ₹26,250

Now, the STT on exercise:

Notional value = 22,400 × 75 = ₹16,80,000 STT at 0.125% = ₹2,100

So your net profit after STT alone is ₹26,250 − ₹2,100 = ₹24,150. In this case, a profit. Fine.

But now run the same example with a tight-expiry trade:

  • Premium paid: ₹5 per unit → total premium = ₹375
  • Expiry: 22,050 (just barely ITM, intrinsic value = ₹50 per unit)
  • Gross profit: (₹50 − ₹5) × 75 = ₹3,375

STT on exercise:

22,050 × 75 × 0.125% = ₹2,067

Net profit: ₹3,375 − ₹2,067 = ₹1,308 — nearly two-thirds of the gross profit consumed by STT alone.

Push the numbers further: if the premium was ₹20 and the intrinsic value at expiry is ₹25, the gross profit is (₹25 − ₹20) × 75 = ₹375. The STT on exercise would be 22,025 × 75 × 0.125% = ₹2,065 — which is more than six times the gross profit. The position is profitable, but you lose money after STT.

This is not an edge case. It happens every expiry, to traders holding barely-ITM options into close.

Why doesn't the broker warn you?

Most brokers display the projected P&L at expiry without accounting for exercise STT. The number in your terminal shows intrinsic value minus your cost. The STT deduction happens post-close, often the same evening, and appears as a debit in your ledger the next morning.

Some brokers have added STT warning banners in recent years, especially after SEBI received complaints. But the default UX still does not surface the effective net yield after exercise STT — the most important number for an expiry-day options holder.

The practical rule: if you're holding ITM options into expiry and your notional contract value is large relative to your profit, consider closing the position before 3:25 PM rather than letting it expire. Closing before expiry triggers only the options sell-side STT (0.0625% on premium) — far less than the exercise STT (0.125% on notional).

How STT affects different F&O strategies

Long options (buyers)

You pay STT only on the exit:

  • If you sell before expiry, STT is 0.0625% on the premium you receive.
  • If the option expires OTM (worthless), no STT is charged — the option simply expires.
  • If the option expires ITM, STT is 0.125% on the full notional value.

The zero-STT case (OTM expiry) is one reason short-dated, far-OTM options are so popular — losing trades are actually cheaper from a tax standpoint than barely-profitable ITM expiries.

Short options (sellers)

When you sell an option, STT is 0.0625% on the premium received immediately. You pay this whether or not the option eventually expires worthless or is exercised against you.

For regular option sellers — strategies like short straddles, covered calls, or iron condors — the STT load is usually manageable because premiums are collected upfront and the 0.0625% rate is applied only to those premiums.

Futures traders

Futures STT at 0.02% on notional turnover sounds small, but on high-leverage, high-turnover futures trading it compounds quickly. A trader doing ₹1 crore in daily futures turnover pays ₹2,000 per day in STT alone — ₹44,000 a month assuming 22 trading days. This is money that has to be earned back before a single rupee of net profit.

STT on Kuber Trade

Kuber Trade is incorporated in the Republic of Panama and operates as a global derivatives platform — it is not a SEBI-registered broker and does not facilitate trades on NSE or BSE directly. Because of this, there is no STT applicable to trades placed on Kuber Trade.

This is one of the platform's clearly stated structural advantages: the regulatory and tax framework that applies to Indian domestic brokers does not apply here. Traders pay no STT, no exchange transaction charges, no SEBI turnover charges, and no stamp duty.

The trade-off is that Kuber Trade is not operating under SEBI's retail investor protection framework. Traders should read the Risk Disclaimer and understand the jurisdiction before trading.

Other transaction costs Indian F&O traders should track

STT is the biggest, but not the only cost:

| Cost | Approximate rate | | --- | --- | | STT (futures sell) | 0.02% of notional | | STT (options sell) | 0.0625% of premium | | STT (options exercise) | 0.125% of notional | | Exchange transaction charges | ~₹190 per ₹1 crore turnover (NSE) | | GST on brokerage + charges | 18% on brokerage | | SEBI turnover charge | ₹10 per ₹1 crore | | Stamp duty | 0.003% on buy side (futures); 0.003% on buy side (options premium) |

When you add all of these up across a typical active trading month, the transaction cost burden can easily exceed 0.1% per round trip on options — which is material for short-duration trades with thin expected edges.

Frequently asked questions

What is STT in F&O trading? STT is Securities Transaction Tax, a government tax collected by the exchange on every trade in Indian equity and derivatives markets. For F&O, it's charged at 0.02% on futures notional (sell side) and 0.0625% on options premium (sell side). For exercised or expired ITM options, a higher rate of 0.125% on full notional value applies.

Is STT charged on buying options? For regular intraday or positional options trades, STT is charged only on the sell side. However, if you hold an ITM option to expiry and it is exercised (or auto-exercised by the exchange), STT at 0.125% on the full notional value is charged to the buyer.

How do I avoid exercise STT? Close your ITM options position by selling in the market before expiry (before 3:25 PM on expiry day). When you sell, you pay only the standard 0.0625% STT on the premium — much lower than the 0.125% on notional that exercise triggers.

Is STT the same as capital gains tax? No. STT is charged at the point of the transaction regardless of whether you made a profit. Capital gains tax is calculated at the end of the financial year on your net realised profits from trading. Both apply — STT is not deductible from capital gains for F&O traders (F&O income is typically treated as business income).

Does Kuber Trade charge STT? No. Kuber Trade is incorporated in Panama and does not operate on NSE or BSE. STT, which is an Indian government levy on NSE/BSE transactions, does not apply to trades placed on Kuber Trade.

This article is for educational purposes only and does not constitute tax or investment advice. STT rates are subject to change by the government. Consult a qualified tax professional for advice specific to your situation. Trading in leveraged derivatives carries a substantial risk of capital loss. See our Risk Disclaimer.