BookPilot's scanners find signals. Its Rules of Engagement decide whether any of them may become an order. Understanding this layer explains most of the "why didn't it trade?" questions new users have.

What the Rules of Engagement check

Every signal that survives the scanners and the optional Forecast Confirm filter is checked against four conditions:

  • The strategy is armed and flat, with no open position and no working entry.
  • The current time is inside the trading window (08:30 to 15:00 exchange time by default).
  • The direction is allowed by the current mode: With Bias, Long only or Short only.
  • The risk preset's hourly trade cap has not been reached.

Behind this sits a small state machine with six states: Disarmed, Armed, Pending entry, In position, Cooldown and Locked. Only an Armed strategy accepts a signal.

The arming buttons

The Chart Trader panel has three ways to arm:

  • With Bias arms both directions but only takes signals that agree with the Microstructure Bias, or any signal while the bias is None.
  • Engage Long arms for long signals only.
  • Engage Short arms for short signals only.

Pressing the active button again disarms. If no Level 2 update has arrived in the last 5 seconds, BookPilot refuses to arm and says why, which usually means the feed has no depth for that instrument or replay is paused.

How the bias is set

The Microstructure Bias comes from the micro-forecast, a logistic model that estimates the probability that the next 2-tick move of the mid price is up. Call that P up.

  • P up at or above the Bias Threshold (0.55) gives a Long bias.
  • P up at or below 1 minus the threshold (0.45) gives a Short bias.
  • Anything in between is None, and in With Bias mode signals in both directions pass.

The setting works in a way that surprises people. Raising Bias Threshold makes None more common, so With Bias blocks fewer signals. Lowering it means there is almost always a bias, so more signals are refused. The suggested range is 0.52 to 0.65.

Auto Re-Arm

Auto Re-Arm is on by default. After every trade BookPilot arms itself again, and after a losing trade it waits for the risk preset's cooldown first. That is the hands-off mode: it keeps trading until a daily gate locks it.

Turn Auto Re-Arm off and BookPilot takes one trade, then disarms. You arm it again by hand. This suits traders who want to approve each opportunity, or who are still learning how the signals behave.

Arm On Start and the default mode

The Rules of Engagement setting (default With Bias) chooses the mode used by Arm On Start. Arm On Start is off by default. When on, BookPilot arms in that mode as soon as Level 2 data is live, without a click. The guide recommends it only when the Chart Trader panel is not available. Normally you arm from the panel at the moment you decide to start.

Reading the Blocked line

When a signal appears but no order follows, the panel's Blocked line names the reason: not armed, outside the trading window, against the bias, the hourly limit or Forecast Confirm. Watching it for a session in Market Replay tells you which rule does most of the filtering on your instrument.

The other panel controls sit alongside: switches for the Pulled Wall and Pressure Break engines, the LOW / MEDIUM / HIGH risk preset, the Forecast Confirm switch, and Flatten All, which cancels the working entry and closes the position at market.

A sensible starting routine

Begin with With Bias and Auto Re-Arm off, so you see each trade individually. Once the Blocked reasons and the fills make sense, switch Auto Re-Arm on. Use Engage Long or Engage Short only when you have a reason to restrict direction for the session, such as a strong view from your higher-timeframe analysis.

The full settings reference is in the BookPilot user guide. The product page summarises the plan, and the comparison page shows how FlowPilot's simpler Arm Long, Arm Short and Arm Both buttons differ.

Rules of Engagement decide when BookPilot may trade, not whether a trade will work, and futures losses can mount quickly. Check that the rules behave as you expect in Market Replay and SIM before an evaluation, funded or live account.