live-price-tracking_skill

Overview

This skill is a practical guide for implementing live price tracking in NinjaTrader 8 strategies to eliminate delayed trailing stops and other real-time decision bugs. It explains the Close[0] pitfall, the OnMarketData pattern, rate-limited order modifications, and fallbacks for stale feeds. Use it to improve intra-bar execution and reduce missed profit opportunities.

How this skill works

It replaces bar-close-dependent logic with tick-level handling via OnMarketData, filtering for MarketDataType.Last and the current instrument. Indicators are cached on bar close and used during ticks to compute stops without recalculating expensive indicators. A rate limiter ensures order changes comply with broker limits and a last-tick timestamp detects data disconnects.

When to use it

• Trailing stops that only update at bar close
• Entry/exit rules that need intrabar accuracy
• Fixing logic that relies on Close[0] for real-time decisions
• Detecting and reacting to data feed disconnects
• Implementing Apex/Rithmic order modification limits

Best practices

• Filter OnMarketData for MarketDataType.Last and e.Instrument == Instrument
• Cache indicators in OnBarUpdate; reference cached values in OnMarketData
• Rate-limit order modifications (e.g., 1 per 1000 ms) to avoid broker penalties
• Use a GetLivePrice() fallback that prefers midpoint (Bid+Ask)/2, then Ask, then Bid, then Close[0]
• Log tick counts and last-tick times to verify feed health and detect disconnects

Example use cases

• Convert a trailing stop that used Close[0] to an OnMarketData-driven update so stops move intra-bar
• Use GetLivePrice() in entry logic on multi-timeframe charts where OnMarketData may not fire consistently
• Add disconnect detection to flatten positions if no ticks arrive for a configured threshold (e.g., 5s during RTH)
• Implement rate-limited ChangeOrder/SetStopLoss to stay within Apex modification rules