--- title: "Must a backtest include STT and costs | RupeeCase" description: "Yes: a backtest that leaves out STT, exchange charges, GST, stamp duty and slippage reports a gross result that no account earned." source_url: "https://www.rupeecase.com/learn/questions/backtest-include-stt" --- The STT on an option sale rose from 0.05% to 0.15% of premium, so a dated backtest needs each date's rate STT rates on options, as a percentage. Sale rates apply to premium and exercise rates to intrinsic value. Each rate applies from the date shown until the next one. Source: NSE/FATAX circulars on STT rates (2016, 2023, 2024 and 2026). As of 1 Apr 2026. A backtest tests the rules on past prices. An account pays costs on every trade: STT, exchange transaction charges, stamp duty, GST on brokerage, and the slippage between the price a rule expects and the price it gets. Leave any of these out and the test measures a gross result that no account can keep. STT is one of the statutory items, and its rates have changed in steps. The chart lists the rates that applied from each date. Since 1 Apr 2026 the sale of an option carries 0.15% of premium, and an option that is exercised is charged on its intrinsic value. Before that date the earlier rates in the chart applied, so a trade from one year and a trade from another do not cost the same. Build the cost into each trade on the date it happened. A flat cost taken from the latest rate hides the change and flatters older years. Keep the costs in a separate table, so each rate can be checked against the NSE circular that set it and a reader can see how much of the result the costs take. The [STT question](/learn/questions/stt-on-options) sets out the rates in full. Costs are not the whole test. Slippage depends on the book, the size and the time of entry, so a backtest that fills at the close needs a stated slippage rule. A result that stays positive after dated, costed and slipped trades is still a test on past data, and an out of sample check has to confirm it. **Before you trade.** Derivatives trading carries a high risk of loss. SEBI's study "Profitability of Individual Traders in the Equity Derivatives Segment (FY25 to FY26)" (August 2026) found that 87.7% of individual traders in equity F&O made net losses in FY26, with aggregate net losses of Rs 91,685 crore. [Read the SEBI study](https://www.sebi.gov.in/reports-and-statistics/research/aug-2026/study-profitability-of-individual-traders-in-the-equity-derivatives-segment-fy25-fy26-_103835.html) Must a backtest include STT and costs?Yes: a backtest that leaves out STT, exchange charges, GST, stamp duty and slippage reports a gross result that no account earned, and STT has changed in steps, so each historical trade needs the rate that applied on its own date. The sale rate is 0.15% of premium from 1 Apr 2026, and an exercise is charged on intrinsic value. LGo deeper ## Where Learn teaches this. [Go deeperThe real cost of a trade: STT, exchange fees, SEBI fee, GST and stamp duty7 min, Beginner](/learn/path-12/module-12-6-cost-of-an-fo-trade)[Go deeperWhat a backtest is, and five biases that ruin it9 min, Intermediate](/learn/path-19/module-19-1-backtest-biases)[Try itF&O costs and STTEvery statutory charge on a trade at the 2026 rates.](/learn/tools/fo-cost-calculator) SSources ## Go to the source. 1. [NSE, equity derivatives securities transaction tax (rates from 1 Apr 2026)](https://www.nseindia.com/static/products-services/equity-derivatives-securities-transaction-tax) NSE 2. [NSE/FATAX/73524, STT rates from 1 Apr 2026 (31 Mar 2026)](https://nsearchives.nseindia.com/content/circulars/FATAX73524.pdf) NSE ?Questions people ask ## Related questions. [QuestionWhat is STT on options and on exercise?Beginner](/learn/questions/stt-on-options)[QuestionHow do I backtest an option strategy in India, or in Python?Intermediate](/learn/questions/backtest-option-strategy)[QuestionHow do people set a stop loss on options, and when do they exit?Beginner, trap check](/learn/questions/stop-loss-on-options)[QuestionHow much capital do I need to trade or sell options?Beginner, trap check](/learn/questions/capital-needed-for-options) [All 130 questions](/learn/questions/) Explore next ## Go deeper on this question. * [QuestionHow do I use Monte Carlo to test strategy risk?A short answer with a dated chart](/learn/questions/monte-carlo-strategy-risk) * [ToolOption payoff builderLegs on a dated Nifty chain, breakevens and charges](/learn/tools/payoff-builder) * [GlossaryInvesting glossary, 230 termsPlain word definitions, and the app’s own](/learn/glossary) Community ## Join my WhatsApp group. Scan the code, fillFill one short form, and join my WhatsApp group. Slides, sources, factsheets and the rebalance logs live there, and members join a daily Google Meet with me. New to RupeeCase? [Getting started](/getting-started) [See the terminal](/terminal) [Sign up for RupeeCase](https://invest.rupeecase.com/signup) [Join the WhatsApp group](https://forms.gle/C6HMtM1Z2GfeocQV7) [One form, one group](https://forms.gle/C6HMtM1Z2GfeocQV7)Scan with your phone camera Education only, not investment advice, a research report or a recommendation to buy, sell or hold any security. RupeeCase (QC Alpha Technologies Pvt Ltd) is not registered with SEBI as an investment adviser or research analyst. Contracts and prices shown are for illustration only, come from NSE end of day files at least 30 days old, and are not recommendatory. Derivatives trading carries a high risk of loss.