Ta4j — Technical Analysis for Java

Welcome to the ta4j wiki, the living handbook for building, evaluating, and deploying TA-driven trading systems on the JVM.
The wiki follows a task-focused layout organized into clear sections:

Start Here

Get up and running quickly with essential guides:

• Home – Overview and quick navigation
• Getting Started – Installation, first steps, and your first strategy
• FAQ – Common questions and answers
• Release Notes – What’s new in each version, migration guides, and breaking changes

Core Concepts

Deep dives into ta4j’s fundamental building blocks:

• Bar Series & Bars – How ta4j models OHLCV market data
• Data Sources – Unified interface for loading data from CSV files, JSON files, Yahoo Finance, Coinbase, and more
• Num – Precision-aware numeric types (DoubleNum, DecimalNum) for calculations
• Technical Indicators – Building blocks for technical analysis
• Moving Average Indicators
• Trendlines & Swing Points – Automated support/resistance detection and swing point identification
• Elliott Wave Indicators – Elliott Wave pattern detection
• Maven Notes – Build configuration and dependency management

Build Strategies

Learn to compose, test, and visualize trading strategies:

• Trading Strategies – Composing rules into complete strategies
• Backtesting – Evaluating strategy performance with historical data
• Charting – Creating professional charts with indicators, trading records, and analysis overlays
• Usage Examples – Real-world examples and patterns

Deploy & Operate

Take your strategies to production:

• Live Trading – Running strategies in live markets
• Backtesting › Analysis & Logging – Performance analysis and debugging
• Bots & Automation – Automating trading workflows

Project & Community

Contribute, report issues, and stay informed:

• How to Contribute – Development setup and contribution guidelines
• Found a Bug? – How to report issues effectively
• Roadmap & Tasks – Planned features and known limitations
• Branching Model – Git workflow and release process
• Alternative Libraries – Other technical analysis libraries for comparison
• Related Projects – Community projects built on ta4j
• XLS Testing – Excel-based testing workflows

What’s new in 0.21.0

Release 0.21.0 (November 29, 2025) introduces unified return representation and enhanced oscillator coverage:

• Unified return representation system – Consistent formatting across all return-based criteria (multiplicative, decimal, percentage, logarithmic) via ReturnRepresentation and ReturnRepresentationPolicy
• Ratio criteria standardization – All ratio-producing criteria now support ReturnRepresentation for consistent dashboard and reporting outputs
• New oscillators – TrueStrengthIndexIndicator, SchaffTrendCycleIndicator, and ConnorsRSIIndicator expand oscillator coverage
• Helper indicators – PercentRankIndicator, DifferenceIndicator, and StreakIndicator for advanced indicator composition
• High-precision improvements – DecimalNumFactory#exp now uses configured MathContext for better precision in exponential calculations
• Breaking changes – EMA indicators now return NaN during unstable periods; DifferencePercentageIndicator deprecated in favor of PercentageChangeIndicator

Previous highlights (0.19)

Release 0.19 focused on production-ready workflows:

• Accelerated backtesting with BacktestExecutor, runtime reports, and streaming top-K selection
• Strategy serialization & presets via StrategySerialization and compact NamedStrategy formats
• Expanded indicator set including Renko brick helpers, MACDV, Net Momentum, and vote-based rules
• Deeper analytics like drawdown Monte Carlo simulation, commission impact, and capital utilization metrics
• Trendline and swing point analysis suite – Automated support/resistance detection with fractal and ZigZag swing indicators
• Unified data source interface – Consistent API for loading data from files, Yahoo Finance, Coinbase, and more

Browse the Release Notes for the complete changelog with migration guidance.

Need help or want to collaborate?

• Join the community Discord to discuss trading ideas, ask questions, or showcase projects
• Explore the ta4j-examples module for runnable samples referenced throughout the wiki
• Open issues or PRs in the main ta4j repository when you spot bugs or have improvements in mind