PaisaOrbit 
By the PaisaOrbit Research Desk. This article is for educational purposes only and does not constitute investment advice — see the disclaimer at the end.
Budget 2026 delivered the sharpest Securities Transaction Tax (STT) increase on derivatives in two decades, effective April 1, 2026. If your F&O strategy runs on thin per-trade margins — scalping, weekly option writing, high-frequency spreads — this isn't a rounding error. Here's exactly what changed and what it costs on a real trade.
What Changed: The New STT Rates for F&O
| Transaction type | Old rate | New rate | Increase |
|---|---|---|---|
| Futures (sell side) | 0.02% | 0.05% | 150% |
| Options — premium (sell side) | 0.10% | 0.15% | 50% |
| Options — on exercise | 0.125% | 0.15% | 20% |
Notice the two options rates converged at 0.15% — selling an option and letting one get exercised now cost the same in STT, where exercise used to be slightly cheaper.
Why the Government Raised STT
The stated goal is curbing excessive speculation in the derivatives segment, particularly high-frequency and weekly-options trading that regulators have repeatedly flagged as a source of retail losses. Raising the futures rate by 150% — far more than the options increases — specifically targets the scalping and short-term futures trades that generate the highest transaction volume relative to profit.
How STT Is Actually Calculated
- Futures: STT is charged only on the sell side, on the total contract value (lot size × price).
- Options (premium): STT is charged only on the sell side, on the premium value (lot size × premium), whether you're buying-to-open-then-selling or writing the option outright.
- Options (on exercise): If an option is exercised or expires in-the-money, STT applies on the settlement/intrinsic value, charged to the buyer.
STT is a flat percentage — it applies whether the trade wins or loses, which is exactly why it matters more for high-frequency strategies than for someone holding a handful of positional trades a month.
Worked Example: STT Cost on a Nifty Futures Trade
Using the current 65 lot size (see our guide to the 2026 Nifty lot size and expiry rules) and Nifty around 25,000:
- Contract value = 65 × 25,000 = ₹16,25,000
- Old STT (0.02%): ₹16,25,000 × 0.02% = ₹325
- New STT (0.05%): ₹16,25,000 × 0.05% = ₹812.50
- Extra cost per sell trade: ₹487.50
That's just one leg. A trader doing 10 round trips a day now pays roughly ₹4,875 more in STT alone, per day — before brokerage, DP charges, or slippage are even counted.
Worked Example: STT Cost on a Nifty Options Trade
Selling 1 lot of Nifty options at a ₹150 premium:
- Premium value = 65 × 150 = ₹9,750
- Old STT (0.10%): ₹9,750 × 0.10% = ₹9.75
- New STT (0.15%): ₹9,750 × 0.15% = ₹14.63
- Extra cost per lot sold: ₹4.88 — a 50% jump, but small in absolute rupees for a single lot
The rupee gap looks trivial on one lot — it stops looking trivial for a weekly options writer running 20-30 lots across multiple expiries a month.
Who Gets Hit Hardest: Scalpers vs. Positional Traders
| Trader type | Trade frequency | STT impact |
|---|---|---|
| Futures scalper | Multiple round trips/day | Severe — 150% rate hike compounds across every trade |
| Weekly options writer | Weekly, high lot count | Moderate — 50% hike, but adds up at scale |
| Positional swing trader | Few trades/month | Minor — STT was already a small fraction of total cost |
| Long-term hedger (Nifty puts) | Occasional | Negligible |
Adjusting Your Strategy for the Higher STT
- Recalculate your breakeven. If your strategy's edge per trade was already thin, add the new STT rate to your cost model before assuming last year's backtest still holds.
- Reduce unnecessary round trips. Every extra sell leg now costs 150% more in STT on futures — exiting and re-entering a position for a marginal reason costs more than it used to.
- Compare total cost, not just STT. STT is one line item alongside brokerage, DP charges, and exchange fees — see our Broker Charges Directory for the rest of that picture before deciding if a broker switch or a strategy change makes more sense.
- Factor it into options-writing math. If you write options weekly, the 50% STT increase is now a fixed line item in your weekly P&L, not a rounding error to ignore.
STT vs. Other Trading Costs: Where It Ranks
For an active F&O trader, STT now sits alongside — and for high-frequency futures scalpers, sometimes above — brokerage as a real cost line. It's not usually the single biggest cost (that's typically brokerage plus slippage for most retail traders), but it's the one cost that's fixed, non-negotiable, and just went up sharply for one specific trading style: short-holding-period futures.
Common Mistakes to Avoid
- Assuming STT is negligible because it "always was." At the old futures rate it often was; at 150% higher, it deserves a fresh look for anyone trading frequently.
- Forgetting STT applies even on losing trades. It's charged on transaction value, not profit — a string of small losses now carries a heavier fixed tax cost on top.
- Mixing up which side gets charged. STT on regular sell trades hits the seller; STT on exercised options hits the buyer — know which applies to your specific trade.
- Not updating an old backtest. A strategy backtested on pre-April-2026 data implicitly used the old STT rates — rerun the numbers with the new ones before trusting the same edge.
Frequently Asked Questions
What is the new STT rate on Nifty futures?
0.05%, up from 0.02% — a 150% increase, effective April 1, 2026, charged on the sell side of the contract value.
Is STT on options higher for buyers or sellers?
Regular STT on the premium is charged to the seller. STT on exercised/expired-in-the-money options is charged to the buyer, on the settlement value — both now sit at the same 0.15% rate.
Does STT apply even if my trade loses money?
Yes. STT is a percentage of transaction value, charged regardless of whether the trade is profitable.
Who is affected most by the 2026 STT hike?
High-frequency futures traders and scalpers see the biggest relative impact, since the futures rate rose 150% versus 50% for options — frequent, short-holding-period trades compound the extra cost fastest.
Disclaimer
This article is for educational purposes only and does not constitute financial, investment, or tax advice. STT rates, thresholds, and rules are set by the Government of India and can change again in future budgets — always verify the current applicable rate with your broker's contract note and official government sources before relying on it for a trading or tax decision. PaisaOrbit is not a SEBI-registered investment advisor.