Paper Trading vs Historical Replay: Which Practice Fits?

Current-market simulation

A quote-driven paper account lets you exercise order submission, modification, cancellation and integration timing as quotes arrive. Record the data source and delay. The simulator may have optimistic or simplified execution compared with the venue.

Historical replay

Replay advances through a supplied recording or bar series. It is useful for repeating a procedure, but exposure to future prices can change your choices. A reset is another look at the same material, not an independent unseen test. Keep your decision log with the data version.

Our lab deliberately reveals one completed bar at a time

Queued market orders fill at the next supplied open after adverse impact and fees. It is daily-bar practice, not tick replay. Your input file remains available locally, so the exercise is not a secured blind assessment. Data gaps move execution to the next supplied row rather than inventing a market calendar.