Discussing the article: "Larry Williams Market Secrets (Part 17) : Detecting Oops Signals Using a Custom Indicator"

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Check out the new article: Larry Williams Market Secrets (Part 17) : Detecting Oops Signals Using a Custom Indicator.

This article implements an MQL5 custom indicator that detects Larry Williams Oops gap reversals and marks bullish and bearish arrows on the chart. It details configurable gap and validity thresholds, same-bar or later confirmation, first-fill-only logic, historical backfilling, and incremental updates so signals remain consistent on both history and newly completed bars.

Identifying Oops gap reversals manually is unreliable because the setup requires tracking several conditions simultaneously. The opening gap must meet a minimum size, the reversal must occur within a limited number of bars, and only the first valid fill should produce a signal. When these checks are performed visually across long chart histories, valid setups may be missed, expired gaps may be treated as active, and the same gap may be marked multiple times.

This article solves the problem by building a custom MQL5 indicator that detects bullish and bearish Oops signals on the price chart. The indicator evaluates completed bars, places arrows at confirmed signal locations, and applies the same rules consistently across historical and newly formed data.

The calculation model is divided into two parts. When the indicator is attached, it scans the available history and maps existing signals into two indicator buffers. After the initial calculation, it updates only the most recently completed bar when new chart data is added. This avoids repeatedly rebuilding the full signal history during normal operation.

Author: Chacha Ian Maroa