Comparison, checked 15 Oct 2026
Opstra simulator vs Tradetron: price, coverage and what comes next
Opstra has been a familiar name among Indian options traders for years, and its Options Simulator is one reason people look it up. The questions we see most are simple. Is the Opstra simulator free? What does it cover? And is there a replay tool that costs nothing? This page answers them from Opstra’s own pricing and help pages as they stood on 15 Oct 2026, next to what the Tradetron option simulator does.
We built the Tradetron simulator, so we have an interest. We have kept to facts each side states publicly, and we say where Opstra does more.
Choose Opstra if you want an established options analytics suite, you value saving trades into portfolios, you already use its Premium plan, and you are comfortable paying a monthly or yearly fee.
Choose Tradetron if you want a replay of past days at 1-minute steps at no charge, with SENSEX and the other four indices in one tool, and a route from what you did by hand to an algo you backtest and deploy with your broker.
| Tradetron | Opstra | |
|---|---|---|
| Is the simulator free? | Yes: preset days with no account, every trading day with a free Tradetron account | No. The Options Simulator is in the paid Premium plan; the free Basic plan does not include it |
| Premium price | No charge | Rs 1,300 a month, Rs 6,000 for 6 months or Rs 11,000 a year, each plus 18% GST |
| What the free tier offers | The simulator itself | Basic plan: Strategy Builder, Results Calendar, Historical Results, with delayed (15-minute) dashboards |
| Exchange coverage on the main site | NSE indices and SENSEX (BSE) | NSE F&O only; BSE and MCX options are on a separate Definedge Securities site |
| Saving trades | Not in the public simulator | Three portfolios; free users keep at most 2 trades, Premium is unlimited |
| Option chain with Greeks | Delta, IV, OI and OI change in the replay | Updates every 15 minutes on the free plan and live on Premium |
Checked on 15 Oct 2026. Features and prices change; check each provider's site.
Is the Opstra simulator free?
No. Opstra describes the Options Simulator as a tool for simulating and backtesting option trades on past expiries, and its pricing table puts it in the Premium plan only. The free Basic plan includes the Strategy Builder, Results Calendar and Historical Results, with dashboards delayed by 15 minutes, but not the simulator. Premium is Rs 1,300 a month, Rs 6,000 for six months or Rs 11,000 for a year, each plus 18% GST. Opstra says all subscriptions are non-refundable, so it is worth trying anything you can before you commit.
The Tradetron option simulator has no charge. Preset days work with no account at all, and a free Tradetron account opens every trading day in the data. That removes the cost barrier for learning, but it is not the only thing to weigh, as the rest of this page shows.
Replay depth: how finely does it step?
Tradetron moves one minute at a time. You can jump from a minute up to an hour, auto-play, or skip to the close. At each step you see the chain as it traded: Delta, IV, open interest and change in OI, with PCR and max pain. Multi-leg positions, partial exits and a trade log are built in, and once you sign in a position can be held across days to expiry, where it settles at the index close.
Opstra’s own pages describe the simulator as covering past expiries, so it is aimed at option traders who think in expiry cycles. They do not say whether the replay steps through the day in minutes or by end of day, and reviews elsewhere disagree, so we make no claim either way. If minute-by-minute entries are what you need, test that on Opstra before paying.
Tradetron never fills a missing price with a model. If a strike did not trade in a minute, you see its last traded price from earlier in the day, greyed out, with the time it traded.
Data coverage: indices and history
Our data starts on 1 January 2020 for NIFTY and Bank Nifty, 3 February 2021 for FINNIFTY, 14 September 2023 for Midcap Nifty and 7 August 2023 for SENSEX, at 1-minute steps. The newest replayable day is about 35 days old: 35-day lag; SEBI requires 30. SENSEX is a BSE index and runs on approximations, since we have no BSE settlement or margin file and its option chain is thinner than NIFTY’s.
Opstra’s main site carries NSE futures and options only. Its BSE and MCX options sit on a separate Definedge Securities site, so a SENSEX trader may need to work across two places. Opstra does not state, on the pages we read, which indices the simulator covers or how far back it starts, so we cannot compare history length. Its backtester covers about 53 tickers and leaves out FINNIFTY because of liquidity, which is a statement about backtesting rather than the simulator.
Analysis tools around the replay
In the Tradetron replay, payoff is live: you see the payoff at expiry and at any target time, with plus and minus 1 and 2 sigma bands and what-if controls for spot and IV, and position Greeks that move with the clock. That is the whole toolset by design. We do not try to be an analytics suite.
Opstra is closer to one. Premium gives a live option chain with Greeks, where the free plan updates every 15 minutes, and a backtester sits alongside the simulator. If you work with a suite of option analytics every day, having the simulator in the same account as those tools is a real advantage. Opstra also lets you file trades into portfolios, which a replay that you open fresh each time does not. Our public simulator has no save, share or import today.
What happens after practice?
A simulator shows you how one trade behaves on one day. The next question is whether the idea holds across many days, and whether you can run it without sitting at the screen.
On Tradetron, the answer continues in the same login. You tell Cookie, our AI, what you did: the entry time, the strikes as distance from ATM, and where you got out. Cookie writes it as an algo with an entry rule and a stop-loss or time exit. You backtest it on years of data, then deploy it with your broker when you are ready. Algo trading carries risk, and a backtest describes the past, not the future. The public simulator does not hand your trades to Cookie on its own; you tell Cookie your setup. See from a manual replay to an algo for a worked example of that step.
Opstra pairs its simulator with an options backtester, so you can test ideas on history inside the same product. We did not find a deploy-with-your-broker step on the pages we checked, so that part of the journey may happen elsewhere.
Where Opstra is stronger
- Track record. Opstra announced its freemium model on 20 Jan 2020 and has been used by options traders since.
- Saved portfolios. It keeps your trades in three portfolios, unlimited on Premium.
- A backtester in the same account. Test an idea on history without leaving Opstra.
- A live chain with Greeks on Premium, next to the simulator.
- A free tier. The Basic plan is free, with a Strategy Builder, even though the simulator is not in it.
Our simulator also runs on a 35-day lag. We do not know Opstra’s lag, because it does not state one.
Who each tool suits
Opstra suits a trader who already thinks in expiry cycles, wants a set of option analytics in one account, and keeps a running record of trades in portfolios. If that is you, the Premium fee buys a mature product, and the lack of a free simulator tier is a trade-off you have probably accepted.
Tradetron suits a trader who wants to practise on days that already happened without paying first. A beginner learning how a straddle behaves through a gap, a trader checking how an exit rule would have worked at 10:30 instead of 11:00, or someone who wants to hold a position over several days to expiry will find the replay enough for that job. It also suits anyone who already suspects they will want to automate a setup, because the same login leads to Cookie, then a backtest, then a deployment with your broker.
Neither is wrong. They answer slightly different questions, and many traders use more than one. For a view across the whole field, see option simulators in India, by use case.
Where to go next
Whatever you choose, try a real day first. A good test of expiry behaviour is a Thursday-expiry session: replay NIFTY on 15 May 2025 from 09:20. To weigh more tools, read the StockMock comparison, the AlgoTest comparison and the Sensibull explainer, or go back to the option simulator.
Questions traders ask
Is the Opstra simulator free?
No. On 15 Oct 2026 Opstra listed the Options Simulator in the Premium plan only. The free Basic plan does not include it. The Tradetron option simulator has no charge.
How much does Opstra Premium cost?
Opstra listed Rs 1,300 a month, Rs 6,000 for 6 months and Rs 11,000 for a year, each plus 18% GST, and says subscriptions are non-refundable. Check Opstra for current prices.
What is the difference between a replay simulator and a backtester?
In a replay you decide each step by hand while the clock moves. A backtest runs written rules over a long stretch of history in one go. On Tradetron, backtesting is a separate feature and the next step once your idea is a set of rules.
Does Opstra cover SENSEX?
Opstra says its main site carries NSE futures and options only, with BSE options on a separate Definedge Securities site. Tradetron includes SENSEX from 7 August 2023, on approximations because there is no BSE settlement or margin file in our data.
Is there a free alternative for replaying past expiries?
The Tradetron option simulator replays past days, including weekly expiry days, at 1-minute steps. Preset days need no account; a free account opens every day in the data. 35-day lag; SEBI requires 30.
Keep reading
- Free NIFTY & Bank Nifty option simulator: replay a real day
- Option simulator: replay a real trading day
- StockMock simulator compared
- AlgoTest simulator compared
- Sensibull virtual trading vs historical replay
- Option simulators in India, by use case
Historical replay for education and analysis. Past prices; not investment advice. Nothing here places orders. Algo trading carries risk.