Follower Guard Logic: What It Is, Why It Matters, and How to Configure It

A trade copier's primary job is replication — making follower accounts mirror the leader. Follower guard is the secondary job: detecting when a follower has drifted from the expected state and alerting you (or automatically correcting it) before the divergence causes a problem.

What Follower Guard Does

Follower guard logic continuously compares the expected state of each follower account (based on what the leader is doing and what the copier has sent) against the actual state of the follower (what the broker says the account is currently holding).

When it detects a mismatch — follower has a position the leader doesn't, follower is flat when the leader is long, follower has a different size than expected — it triggers an alert and, depending on configuration, can take automatic corrective action.

The key scenarios follower guard catches:

• Missed entry — leader entered a trade, follower didn't. Copier log shows the order was sent, but the follower is flat.
• Orphaned position — leader closed a trade, follower is still holding. The close order failed to replicate for any reason.
• Size mismatch — follower holds a different contract count than the ratio-adjusted expected size.
• Stale position — follower is holding a position that the copier has no record of sending. Usually a remnant from a previous session that didn't close cleanly.

Reactive vs. Proactive Guard

There are two implementation approaches for follower guard:

Reactive guard (Replikanto's approach): runs on a polling cycle — checks follower state every N seconds and compares against expected state. Simple and reliable for catching divergences, but has a detection latency equal to the polling interval. A divergence that happens 1 second after a check won't be caught for N-1 more seconds.

Proactive/event-driven guard (Copilink's approach): monitors follower account state changes in real time via NinjaTrader's internal event system. When a follower's position changes unexpectedly — an order fills that the copier didn't generate, or an expected fill doesn't arrive — the guard triggers immediately rather than on the next polling cycle.

For fast markets and intraday trading, event-driven guard provides faster divergence detection — you're alerted within milliseconds of a mismatch occurring rather than within N seconds of the next polling cycle.

Configuring Follower Guard Thresholds

The main configuration decision for follower guard is what constitutes a "mismatch" worth alerting on. A few settings to consider:

Size tolerance. Due to contract ratio calculations and rounding, a follower's position size may differ from the exact mathematical ratio by 1 contract. Setting a size tolerance of ±1 contract prevents false positives from rounding while still catching genuine size divergences.

Entry timing tolerance. After the leader enters, followers enter sequentially — the last follower might be 15-30ms after the first. The guard should not flag this as a missing entry immediately. Set a minimum delay before reporting a follower as "missing" an entry — 2-5 seconds is typically appropriate.

Automatic corrective action vs. alert only. For orphaned positions (follower holding after leader closed), automatic corrective close is generally safe — you want the follower flat. For missed entries, automatic corrective entry is riskier — the market may have moved significantly since the leader's entry, and entering at current price may not make sense. Alert-only is the safer default for missed entries; let the trader decide.

Monitoring the Guard During Live Sessions

Follower guard alerts should be visible during active trading — not buried in a log you check after the session. Configure alerts to appear in a prominent position in your NinjaTrader workspace so a divergence notification during a live trade gets your attention immediately, not 20 minutes later when you're reviewing logs.

The Copilink dashboard surfaces follower guard alerts alongside the per-account risk status — one panel shows connection status, position state, daily P&L, and any divergence alerts across all accounts simultaneously. For managing 10+ accounts, this consolidated visibility is essential.