Method
Bar replay: backtesting by replaying the market candle by candle
6 min read · by the GetBacktest team
Bar replay (or market replay) means replaying a historical chart as if it were unfolding live: candles appear one at a time, and you decide blind to the future. It's both the most honest form of manual backtest and the best practice simulator — close to live, but without risking a cent.
The principle
You pick an instrument, a period and a timeframe, then move through history candle by candle. At each step you see the past and the present, never the future. You place your entries, stops and targets exactly as live.
That constraint — never seeing the next candle — is what separates bar replay from simply reading a chart, where the eye cheats by already knowing what follows.
Manual or automated
Manual replay is ideal for discretionary strategies and for learning: you feel every decision — the waiting, the doubt, managing an open trade. Automated backtesting tests faster but reproduces your biases if the rules are fuzzy.
The two are complementary: refine an idea in manual replay, then validate it over a large sample. Neither is worth anything without anti-look-ahead protection.
Tick by tick or candle by candle
In candle mode, price jumps from one close to the next. In tick mode, price moves inside each candle, as in reality: your stop or target can be hit along the way, in the order it truly happened.
Tick mode makes fills far more realistic — crucial for tight-stop strategies or multiple targets, where the order of intra-candle events changes the outcome.
Why it's the best practice
Bar replay compresses months of market into one session: you accumulate hundreds of decisions and trades without waiting for real time, while keeping the emotional texture of live trading.
On GetBacktest, replay runs on real data, the future is hidden server-side, and every session feeds your statistics (expectancy, drawdown, robustness). It's measurable practice, not mere observation.
Don't believe it — prove it
Backtest this concept on real data, tick by tick, and get a robustness verdict. 7 days of Pro free, no card.
Start for freeFrequently asked questions
Are bar replay and backtest the same?
Bar replay is a form of backtest — manual backtesting, by replaying history candle by candle. Automated backtesting instead runs coded rules with no intervention.
Is tick mode really useful?
Yes, whenever the order of events within a candle matters (stop and target close together). It avoids skewing results by naively assuming which level was hit first.
Where can I do bar replay on real data?
On GetBacktest: candle or tick replay on real market data, future hidden server-side, and robustness statistics computed automatically.
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