Fair Value Gaps - indicator for MetaTrader 5

Detects bullish and bearish fair value gaps (three-candle imbalances) on closed bars only, so zones don't repaint, and tracks each zone until it's mitigated. Zone state and price levels are exposed through iCustom buffers, so an EA can read them without parsing chart objects.

A bullish gap is formed when the high of candle 1 is below the low of candle 3; a bearish gap is the mirror. Bar 0 is never used for detection or mitigation. Each zone is drawn as a rectangle that extends right until it's mitigated.

Zone states: 0 none, 1 active, 2 touched, 3 mitigated. "Touched" means partially filled: price entered the zone but didn't cross it. It only occurs in MIT_FULL_FILL mode; in MIT_TOUCH the first entry mitigates the zone.

iCustom buffers (not plotted, visible in the Data Window). Values are written on the bar of candle 3, the bar where the gap is confirmed:

• 0: state (0–3), updated as the zone changes
• 1: top price (EMPTY_VALUE if no gap)
• 2: bottom price (EMPTY_VALUE if no gap)
• 3: direction (+1 bullish, -1 bearish, 0 none)

Zones dropped by InpMaxZones keep their last buffer state.

int h = iCustom(_Symbol, _Period, "FairValueGaps");
double st[1], top[1], bot[1], dir[1];
if(h != INVALID_HANDLE &&
   CopyBuffer(h, 0, 1, 1, st)  == 1 && CopyBuffer(h, 1, 1, 1, top) == 1 &&
   CopyBuffer(h, 2, 1, 1, bot) == 1 && CopyBuffer(h, 3, 1, 1, dir) == 1 &&
   dir[0] != 0)
   PrintFormat("FVG on bar 1: dir %d, %.5f-%.5f, state %d", (int)dir[0], bot[0], top[0], (int)st[0]);

No alerts, no trading, no DLL or WebRequest. Chart objects use the FVGZ_ prefix and are removed with the indicator.