About the backtester
What data does the backtester use?
Indicator strategies use 1-minute candles of the main indices and every F&O stock (from 2016 onwards, still downloading). Option strategies use the option chains we record every minute, from 3 November 2026.
How are trades filled?
A signal on a bar's close is traded at the next bar's open, so the test never uses prices it could not have known. Option sells fill at the recorded bid and buys at the ask. Add your brokerage and taxes as a cost per trade.
Is a good backtest a guarantee?
No. Past results do not predict future ones, and real fills can be worse. Use it to compare ideas, not as advice.