Mechanism
Many FX/CFD/crypto venues are not centralized. Different feeds can print different highs/lows.
Stops trigger off your broker's quotes. Disputes are judged against their reference feed, not your chart screenshot.
If your strategy is sensitive to a few ticks, your feed is part of the strategy.
Execution reality: the market you backtested is not the market you trade. Spreads are stateful, liquidity is time-of-day dependent, and fills degrade exactly when your stop becomes most sensitive.
- Track spread-to-ATR (or spread-to-range) as a live risk input, not a “cost”.
- When spreads widen, your effective stop tightens and your R:R collapses.
- If your edge needs perfect fills, your edge is mostly fictional.
How it kills accounts
Assume universal price → place tight stops → broker feed prints spike → stop triggers → trader claims 'never happened' → dispute fails → trust collapses.
How it kills accounts:
- Edge looks fine in backtest.
- Live spreads widen at the exact wrong moments.
- Stops trigger inside noise, so you widen stops.
- Same size + wider stop = silent leverage increase.
- A normal spike becomes structural damage.
Rule that survives
Know your broker's price source and how they define off-market ticks.
Do not trade tick-sensitive strategies on ambiguous feeds.
If execution quality matters, choose venues with stronger transparency.
Rule that survives:
- Spread is a gate, not a footnote. If it’s abnormal, you don’t trade or you trade smaller.
- Assume worst-case fills in fast markets.
- Size is the adapter: reduce size before changing the stop model.
Example archetype
Your TradingView chart never shows the spike. Your broker feed does. Your stop triggers. The outcome is determined by the feed you actually trade, not the feed you admire.
Tell: if the trade only works when the spread is tight and price is smooth, it’s not an edge, it’s a regime bet.
Deep dive
Broker reality crossover
This is where execution meets contracts. If you cannot answer ‘what price source triggers my stop?’, you are exposed.
Glossary: discretion, conflict of interest, invalidation.
Field checklist
- Measure spread before entering. If it’s abnormal, you’re trading the wrong product at the wrong time.
- If volatility expands, reduce size first. Don’t “solve” it by widening stops with the same size.
- Avoid the predictable liquidity holes: rollover, session open/close, first minutes after data.
- Assume your stop may fill worse than your entry. Price the worst-case, not the brochure.
- If you cannot explain where liquidity comes from, trade smaller.