Market Replay
Re-playing recorded market data tick by tick — watching a past session unfold as if it were live.
What it means
Replay takes a recorded session and streams it back through the same charts and factors used live. You watch the book, the tape and your signals evolve second by second — the difference between reading a trade's summary row and watching the trade happen.
For debugging automated systems it is the strongest tool available: when live and backtest disagree, replaying the exact recorded seconds around a trade shows which input actually differed, instead of guessing from aggregates.
Why traders care
- Turns every recorded day into unlimited deliberate practice.
- Root-causes live-vs-backtest mismatches with evidence, not theories.
Related terms
Educational content, not investment advice. Engine details describe how TraderWe computes this value; other platforms may define it differently.