FX options desks work in delta space, not strike space. Standard quotes per expiry are ATM volatility, 25-delta risk reversal, and 25-delta butterfly, with optional 10-delta wings. Strikes are derived from these pillars plus an interpolation choice. Equity-style tooling in MetaTrader 5 commonly starts from listed strike chains and single-rate Black-Scholes. For FX this misses both market quoting practice and the two-rate setup required for carry. A correct implementation uses Garman-Kohlhagen and treats delta as a convention: spot vs forward delta, and premium-adjusted vs unadjusted. The convention varies by pair, premium currency, and tenor, and can shift 1Y strikes by tens of pips or more without triggering obvious errors. The reconstruction pipeline converts RR/BF to wing vols, then solves each pillar’s delta back to its strike at that vol. Outpu... #MQL5 #MT5 #FXOptions #Strategy https://t.co/EvsjHZWVGJ