What is a FOK (Fill or Kill) Order?

Understanding FOK (Fill or Kill) Orders

A Fill or Kill (FOK) order demands immediate and complete execution at the requested price, or it cancels entirely. Traders use FOKs when partial fills are unacceptable—common for large orders seeking to avoid execution slippage.

When to Use FOK

Institutional traders might deploy FOK orders to capture fleeting arbitrage opportunities or to protect against spreading risk across multiple fills. Retail traders can use FOK when liquidity is thin and they only want the trade if full size executes instantly.

Limitations

FOK orders fail frequently in fast markets. If you consistently receive cancellations, consider IOC orders or adjust size and price tolerance.

Example

You need 1M notional at 1.1000 during London. Level‑2 shows ~1.2M within 1 pip—FOK is reasonable. In late Asia with only 200k visible, a FOK will likely cancel; switch to IOC clips or wait for liquidity.

Deep Dive

Most edges come from applying clear rules consistently. Expand your analysis beyond a single signal: add context from higher timeframes, recent volatility, session behavior, and catalysts. Define invalidation so a trade becomes obviously wrong fast, keeping losses small while letting winners compound.

Trader Checklist

• Higher‑timeframe bias aligns with the setup.
• Clear level or zone for entry with confluence.
• Pre‑defined stop beyond structure; 2–3R target.
• Session/liquidity supports follow‑through.
• No imminent high‑impact news unless planned.

Strategy Ideas

• Combine structure with momentum confirmation (break/close/acceptance).
• Use partials: scale out at first target; trail remainder.
• Journal results by session and pair to refine timing.

Risks and Limitations

• Thin liquidity widens spreads and distorts signals.
• False breaks around obvious levels—wait for acceptance.
• Overfitting indicators; keep the process simple and robust.

Example

Map bias on the daily chart, mark a zone, and wait on 1H for a close back above with rising participation. Enter on the retest; stop beyond the invalidation wick; target prior swing with room for extension. Record the outcome and context to iterate.