MQL4 and MQL5 Programming Articles

The series develops state persistence for MQL5 Expert Advisors. Part 1 delivers a crash-safe key-value store: a CStateStore class that saves through a temporary file and a rename, carries a versioned header with a checksum, and stores integers, doubles, strings, booleans, and double arrays, plus a demo advisor that resumes a counter and a rolling window after a restart. Readers get a compact include file and a pattern that protects the live state file if the process dies mid-save.

We implement Symbolic Fourier Approximation in MQL5 and compare it to SAX under a shared harness on identical price windows. SFA keeps low‑frequency Fourier coefficients and learns per‑position bins (MCB), with a proven, sound lower bound. The measurements show how the same bit budget behaves under different splits of word length and alphabet, and give a practical rule for choosing settings for your symbol.

The article presents a compact dashboard that relates trade duration to net profit using MQL5 and CCanvas. It pulls closed deals, derives duration in minutes, and renders a log‑scaled scatter by symbol, with an overlaid least‑squares line and R². A bucketed duration view identifies which hold‑time range produced the highest average result, helping assess exit timing.

In this article, we will explore the ST-Expert framework, which ensures the robustness of forecasts under market uncertainty by taking local and global dependencies in time series into account. Its flexible architecture promotes model adaptability and improves the accuracy of predictions.

The article implements intrinsic-time analysis in MQL5: an event-based directional-change operator that splits ticks into directional-change and overshoot sections. We reproduce the core scaling laws on 17.8 million live EUR/USD ticks and compare them to a random-walk baseline. Finally, we build a hedging-account Expert Advisor that trades the Alpha Engine with limit orders, detailing thresholds, inventory skew, and liquidity control for practical reuse.

The study implements five historical-variance estimators in MQL5 and evaluates their one-session-ahead persistence forecasts for EURUSD D1 sessions using an M1 realized-variance proxy. Deterministic tests cover formulas, chronological order, and target construction. A configurable indicator, comparison scripts, and CSV outputs provide reproducible losses, calibration diagnostics, a common‑target mask, and sensitivity to the estimation window.

A modular MQL5 toolkit computes and visualizes rolling Profit Factor over fixed trade-count windows. It presents the statistical motivation, an incremental algorithm that avoids recomputation, and a dedicated CCanvas rendering pipeline. The dashboard adds reference lines, shading for weak periods, and summary metrics, while a separate test suite validates the math, giving a practical way to monitor stability and detect deterioration in strategy behavior.

This article defines a Protocol Buffers contract for the MetaTrader 5-Python boundary and implements a length-prefixed Protobuf-over-TCP client in MQL5, since MQL5 cannot speak real gRPC natively. A small Python shim relays those frames to a genuine grpc.aio server, unary today, with streaming already live on the backend. You get schema-enforced, strongly-typed messages, explicit errors, retry/backoff, and a Strategy Tester cache for reproducible backtests where sockets don't run.

This article reframes performance from unconditional win rate to conditional probability given survival time. It introduces an MQL5 library, an on‑chart indicator, and a demo Expert Advisor that read deal history, fit Kaplan–Meier and Aalen–Johansen curves with competing risks, and report forward probabilities over a bar‑based horizon. Readers gain a reproducible way to quantify the chance that the current position reaches its target or stop, and to see the bias of the naive censoring approach.

This article extends the candlestick encoding framework by separating previously unclassified bullish and bearish candlesticks into distinct symbols. Using an MQL5 script, historical data were automatically encoded, sequential patterns were extracted, and frequency statistics were generated. The results show that these newly identified candles represent a significant portion of market activity, revealing structural information previously hidden by the generic underscore notation. The expanded taxonomy improves the completeness of the symbolic representation while preserving an objective, quantitative framework for large-scale market structure analysis.

This article implements a lightweight feature-space drift guard in MQL5 using 1D Wasserstein‑1: sort-and-pair scoring on equal windows, IQR normalization per feature, and gating via both a weighted composite and a max-statistic. Configuration comes from a JSON manifest (window sizes, weights, warn/critical thresholds, actions). It runs next to an ONNX classifier and is validated with Strategy Tester results and explicit caveats.

We implement three MQL5 classes that replace fixed 1R/2R/3R targets with data-driven scale-out levels. CExcursionTracker records each closed trade's maximum favorable excursion in R, CExitLadderCalibrator derives runs from distribution percentiles with lookback and minimum-sample controls, and CLadderExecutor executes them on open positions. The ladder recalibrates as trades accumulate and uses a fallback until enough samples exist.

This article builds a usable roughness index from rough volatility theory by fitting local H via a structure-function regression on blocked returns, all in native MQL5. We combine it with vol-of-vol features, train a gradient-boosted classifier in Python, export to ONNX, and call it from an EA. You will be able to compute H on every bar and use the model as a regime-aware entry filter.

The rasterizer now accumulates exact span coverage in X and sampled coverage in Y, and blends it via CairoBlendOver on straight ARGB. CairoAaSamples sets the number of vertical samples at runtime, making the cost nearly linear and localized to edges. Readers get smoother boundaries, correct compositing of translucent shapes, and controllable performance.

The article discusses the implementation of the Artificial Searching Swarm Algorithm (ASSA) in MQL5 as part of a unified test bench. The article examines three behavioral movement rules, the signal and global bulletin board mechanisms, space normalization, and the stepRatio and Pc parameters. Readers will receive a ready-made foundation for integrating ASSA, as well as an answer to the question of how successful the tactical metaphor proved to be as a basis for the competitiveness of the optimization algorithm.

Aggregate metrics like win rate or profit factor miss sequence-dependent behavior, such as sizing up right after a loss. This MQL5 script trains a small native neural network on closed-deal history to estimate loss probability from behavioral and market-context features. It reports accuracy uplift over a baseline, probability calibration, and permutation feature importance, then combines them into a configurable A-F grade with concise, plain-language recommendations.

Part 3 implements a scanline rasterizer in pure MQL5. We convert path segments into top‑down edges, sweep each row, sort crossings, and apply the non‑zero winding rule to decide which pixels are inside. The result is a single Fill(path, color, buffer, w, h) routine that draws rectangles, stars, glyphs, or 2000‑edge shapes without per‑shape code, ready to integrate into your MQL5 projects.

A complete MQL5 implementation of the Ljung-Box test helps verify independence in trading data and fitted-model residuals. It computes sample autocorrelations, the Q statistic over selected horizons, degrees of freedom with user-controlled adjustments, and right-tail p-values via the regularized incomplete gamma function. Run it on returns, deal outcomes, or external residuals and review decisions directly in the Experts tab.