Pine Script is the programming language built into TradingView, a web-based charting platform, and maintained by the same company. It is a compact scripting language designed for one job: calculating values from price bars and drawing them on a chart. Users write indicators for technical analysis, alert conditions, and strategies, which are scripts containing entry and exit rules that the platform can run against past data as a form of backtesting.
The language is easy to learn, and a rule such as a moving average crossover takes only a few lines. Its limits follow from its design. Scripts work only inside TradingView and operate on bars, not on individual ticks or order book data. The built-in strategy tester makes simple assumptions about fills and costs. Some scripts also repaint, meaning that values shown on past bars differ from those available in real time, a source of look-ahead bias. Orders reach a broker only through alerts or supported integrations.