Custom Indicator
Platforms & ToolsA user-added technical study, coded in MQL or Pine Script, that plots its own calculation on a chart without placing orders.
A custom indicator is a user-written or third-party technical study added to a charting platform beyond its built-in tools. On MetaTrader it is compiled from MQL4 or MQL5 source; on TradingView it is written in Pine Script. Once attached, it draws lines, histograms, arrows or coloured zones produced by its own calculation on price and volume data. Unlike an Expert Advisor, a custom indicator normally only displays information and does not send orders, although an EA or a discretionary trader can read its output as a signal. Two things are worth checking before relying on one: whether it repaints, meaning past signals are redrawn as new bars arrive, and how heavily it loads the terminal across many charts.