# FX Global Code Last Look Execution | FXOpen Ledger

> FX Global Code Last Look Execution research topics and source records from FXOpen Ledger. Under FX Global Code Principle 17, wholesale foreign exchange market makers applying last-look checks must enforce disclosed price-tolerance symmetry, eliminate discretionary hold delays, and isolate rejected order data from dealing desk algorithms.

Canonical: https://fxopenledger.com/topics/fx-global-code-last-look-execution
Last updated: 2026-11-14T19:47:31.125Z

## FX Global Code Last Look Execution

FX Global Code Last Look Execution research topics and source records from FXOpen Ledger. Under FX Global Code Principle 17, wholesale foreign exchange market makers applying last-look checks must enforce disclosed price-tolerance symmetry, eliminate discretionary hold delays, and isolate rejected order data from dealing desk algorithms.

Last updated: 2026-11-14T19:47:31.125Z

### Research briefings (20)

- [FX Global Code Principle 17, Last-Look Hold Windows & OTC Execution TCA Guide](https://fxopenledger.com/orderbook/fx-global-code-principle-17-last-look-tca-institutional-guide) — FX Global Code Last Look Execution. Under FX Global Code Principle 17, wholesale foreign exchange market makers applying last-look checks must enforce disclosed price-tolerance symmetry, eliminate discretionary hold delays, and isolate rejected order data from dealing desk algorithms.
- [Auditing GFXC Liquidity Provider Cover Sheets: Last-Look & Hold-Time Metrics](https://fxopenledger.com/orderbook/gfxc-liquidity-provider-cover-sheet-last-look-audit-metrics) — FX Global Code Last Look Execution. Standardized GFXC Liquidity Provider Disclosure Cover Sheets expose critical execution disparities across OTC foreign exchange market makers, including reference mid-price sources, maximum hold-time caps, and internal order-routing firewalls.
- [Firm vs Last-Look OTC FX Liquidity Streams: Spread vs Reject Cost Math](https://fxopenledger.com/orderbook/firm-liquidity-vs-last-look-otc-fx-stream-reject-economics) — FX Global Code Last Look Execution. Tighter headline bid-ask spreads on conditional OTC foreign exchange streams frequently mask 0.45 to 1.15 bps of secondary replacement slippage when simultaneous multi-venue sweeps trigger last-look rejections.
- [Symmetric vs Asymmetric Last-Look Price-Tolerance Checks in Spot FX](https://fxopenledger.com/orderbook/symmetric-vs-asymmetric-last-look-price-tolerance-thresholds) — FX Global Code Last Look Execution. Asymmetric last-look price checks—where an FX dealer rejects adverse client fills while retaining favorable price moves—extract a one-way digital straddle option prohibited under GFXC Principle 17 and FCA/NYDFS enforcement precedents.
- [Spot FX Hold-Time Latency Distributions (0ms-50ms) & Tail Reject Spikes](https://fxopenledger.com/orderbook/spot-fx-hold-time-latency-distributions-zero-to-fifty-ms) — FX Global Code Last Look Execution. Empirical round-trip telemetry across institutional spot foreign exchange feeds reveals distinct latency clusters—sub-2ms ZAHT gates, 5ms-15ms aggregator pass-throughs, and 25ms-50ms legacy hold timers—that govern adverse mid-price drift.
- [FX Global Code Principle 11: Pre-Hedging Rules & Client Consent Boundaries](https://fxopenledger.com/orderbook/fx-global-code-principle-11-pre-hedging-disclosure-boundaries) — FX Global Code Last Look Execution. FX Global Code Principle 11 permits dealer pre-hedging only when acting as principal with prior client disclosure, clear intent to benefit the customer, and strict controls preventing adverse market impact on competitive RFQs.
- [Post-Trade FX Markout Curves (+5ms to +60s): Adverse Selection Diagnostics](https://fxopenledger.com/orderbook/post-trade-fx-markout-curves-five-ms-to-sixty-second-decay) — FX Global Code Last Look Execution. Millisecond-to-minute post-trade foreign exchange markout curves decompose execution performance from T+5ms to T+60s, pinpointing whether post-fill mid-price drift stems from natural signal alpha, premature hedge footprint, or LP quote leakage.
- [Zero Additional Hold Time (ZAHT) in FX Streams: Engineering & Audit Guide](https://fxopenledger.com/orderbook/zero-additional-hold-time-zaht-last-look-implementation-audit) — FX Global Code Last Look Execution. Zero Additional Hold Time (ZAHT) eliminates artificial pause timers in OTC foreign exchange last-look checks, yet execution quality still depends on whether the LP anchors price validation at network ingress or post-queue engine evaluation.
- [Rejected FIX Order Information Leakage: Auditing Last-Look Quote Drift](https://fxopenledger.com/orderbook/last-look-information-leakage-rejected-fix-order-footprints) — FX Global Code Last Look Execution. Information leakage from rejected OTC foreign exchange orders occurs when an unaccepted FIX trade request triggers automated quote skewing or algorithmic hedging—violating FX Global Code Principle 17 confidential handling mandates.
- [Implementation Shortfall TCA Against Arrival Mid for OTC FX Algos](https://fxopenledger.com/orderbook/implementation-shortfall-arrival-mid-tca-for-otc-fx-algos) — FX Global Code Last Look Execution. Benchmarking OTC foreign exchange algorithms against interval TWAP or VWAP hides self-inflicted market impact; Arrival-Mid Implementation Shortfall isolates decision delay, child-slice spread capture, and unexecuted opportunity cost.
- [WMR 16:00 London FX Benchmark: Window Impact & Pre-Hedging TCA Audit](https://fxopenledger.com/orderbook/wmr-4pm-london-benchmark-pre-hedging-and-window-impact-tca) — FX Global Code Last Look Execution. Executing passive portfolio currency rebalances at the FTSE Russell WMR 16:00 London FX Benchmark concentrates month-end demand into a five-minute window, generating predictable pre-fix drift and sharp post-16:02:30 mean reversion.
- [Multi-Dealer RFQ Panel Sizing in OTC FX Swaps: Signaling vs Competition](https://fxopenledger.com/orderbook/rfq-panel-size-signaling-cost-in-disclosed-otc-fx-swaps) — FX Global Code Last Look Execution. Polling six or eight dealers simultaneously on a disclosed OTC foreign exchange swap RFQ widens individual bank quotes via the winner curse and leaks block inventory intent across interbank forward desks.
- [FIX Tag 39 & Tag 103 Reject Code Forensics in OTC FX Aggregators](https://fxopenledger.com/orderbook/fix-tag-39-ordstatus-reject-code-forensics-in-fx-aggregators) — FX Global Code Last Look Execution. Lumping every rejected FIX ExecutionReport into a single fill-ratio KPI blinds OTC foreign exchange desks; parsing Tag 103 OrdRejReason and normalized Tag 58 reason codes separates Prime Broker NOP breaches from LP last-look tolerance rejects.
- [GFXC Algo Due Diligence Templates: Auditing Child-Order FX Routing](https://fxopenledger.com/orderbook/algo-due-diligence-template-gfxc-child-order-routing-audit) — FX Global Code Last Look Execution. The Global Foreign Exchange Committee FX Algo Due Diligence Template standardizes buy-side scrutiny of bank execution algorithms, exposing whether child slices preferentially route into affiliated principal market-making books.
- [MiFID II Best Execution Governance for OTC FX Dealers Post-RTS 27/28](https://fxopenledger.com/orderbook/mifid-ii-rts-28-best-execution-governance-for-otc-fx-dealers) — FX Global Code Last Look Execution. Although EU and UK lawmakers repealed burdensome RTS 27 and RTS 28 public venue tables, core MiFID II Article 27 and FCA COBS 11.2A substantive best-execution surveillance for OTC foreign exchange derivatives remains strictly enforced.
- [Spot FX Fill-Ratio Decay Across 1M, 5M & 25M Clips in G10 vs EM Pairs](https://fxopenledger.com/orderbook/fill-ratio-decay-by-ticket-clip-size-in-g10-and-em-spot-fx) — FX Global Code Last Look Execution. Top-of-book OTC foreign exchange streams routinely achieve 94%+ fill rates on $1M clips, yet conditional acceptance plunges below 68% on $15M-$25M sweeps across Scandinavian and emerging-market currency pairs.
- [Passive Mid-Peg vs Aggressive Sweep Child Execution TCA in Spot FX](https://fxopenledger.com/orderbook/passive-peg-vs-aggressive-sweep-child-execution-tca-metrics) — FX Global Code Last Look Execution. Resting passive bid/offer or mid-peg child orders in fragmented OTC foreign exchange venues earns half-spread optically, yet adverse fill selection ("toxic passive fills") frequently erodes 60% to 85% of that gross spread capture.
- [Cross-Atlantic Latency Arbitrage vs Legitimate Last-Look Defense](https://fxopenledger.com/orderbook/latency-floor-arbitrage-and-stale-quote-protection-in-last-look) — FX Global Code Last Look Execution. Hollow-core fiber and millimeter-wave links carry CME Aurora and NY4 price shocks to London LD4 14 milliseconds ahead of standard subsea cables—defining the exact microstructural boundary of legitimate Principle 17 stale-quote defense.
- [Single-Dealer Platform (SDP) FX Internalization Ratios & Markout Skew](https://fxopenledger.com/orderbook/internalization-ratio-disclosures-on-tier-1-bank-fx-platforms) — FX Global Code Last Look Execution. Tier-1 global banks internalize 75% to 90% of G10 spot foreign exchange volume inside proprietary Single-Dealer Platform books—compressing visible primary CLOB volume while creating zero-footprint execution opportunities for benign flow.
- [Quarterly FX LP Scorecard Design: Weighting Spread, Hold Time & Markouts](https://fxopenledger.com/orderbook/quarterly-lp-scorecard-governance-for-buy-side-fx-desks) — FX Global Code Last Look Execution. Institutional foreign exchange execution committees govern counterparty panels through quantitative quarterly LP scorecards that penalize reject chasing, +500ms hedge dumping, and P99 hold-time breaches alongside raw quoted spread.

### Related entities (11)

- [Bank for International Settlements (BIS)](https://fxopenledger.com/pairs/bank-for-international-settlements) — International financial institution owned by member central banks that publishes the Triennial Central Bank Survey of Foreign Exchange and OTC Derivatives Markets.
- [FX Transaction Cost Analysis (TCA) Implementation Shortfall](https://fxopenledger.com/pairs/fx-tca-implementation-shortfall) — Quantitative post-trade execution benchmark measuring the total basis-point difference between the arrival mid-price at order inception and the final volume-weighted execution price.
- [GFXC Standardized Liquidity Provider Disclosure Cover Sheet](https://fxopenledger.com/pairs/gfxc-lp-disclosure-cover-sheet) — Standardized disclosure template mandated by the Global Foreign Exchange Committee to establish transparency on last-look hold times, symmetry, and pre-hedging.
- [Global Foreign Exchange Committee (GFXC)](https://fxopenledger.com/pairs/global-foreign-exchange-committee) — Global forum of central banks and market participants maintaining the FX Global Code of conduct for wholesale foreign exchange markets.
- [Minimum Quote Life (MQL) ECN Rule](https://fxopenledger.com/pairs/minimum-quote-life-mql) — Electronic matching engine rule requiring resting maker limit orders to remain executable for a mandatory millisecond threshold before cancellation is permitted.
- [Order-Book Depth Resiliency Half-Life (FX)](https://fxopenledger.com/pairs/orderbook-depth-resiliency-halflife) — Microstructural metric measuring the elapsed time in seconds required for top-5-level order-book liquidity to recover 50% of its pre-announcement depth following a macro shock.
- [FTSE Russell WMR 16:00 London FX Benchmark](https://fxopenledger.com/pairs/wmr-4pm-london-fx-benchmark) — Primary institutional foreign exchange spot benchmark calculated over a five-minute window (+/- 2.5 minutes) around 16:00 London time for portfolio valuation.
- [Volume-Synchronized Probability of Informed Trading (VPIN)](https://fxopenledger.com/pairs/vpin-toxicity-metric) — High-frequency microstructure metric measuring order-flow toxicity in volume time rather than clock time to predict imminent liquidity-provider adverse selection.
- [1-Month Non-Deliverable Forward (NDF) Standard Contract](https://fxopenledger.com/pairs/1m-non-deliverable-forward-ndf) — Cash-settled short-dated foreign exchange derivative where counterparties settle the net USD difference between the contracted NDF rate and the official central bank fixing rate.
- [Covered Interest Parity (CIP) Cross-Currency Basis](https://fxopenledger.com/pairs/covered-interest-parity-basis) — The spread discrepancy between the direct cash USD funding rate and the synthetic USD interest rate implied by foreign exchange spot and forward swap points.
- [FX Prime Brokerage Designation Notice (Give-Up)](https://fxopenledger.com/pairs/fxpb-designation-notice) — Tri-party legal instrument under which a Tier-1 Prime Broker authorizes an executing dealer or ECN to execute FX transactions in the Prime Broker’s name on behalf of a designated client.