Kastor vs Mobius (2026)
A side-by-side comparison of Kastor and Mobius on pricing, features, and fit, so you can decide which is right for you.
Quick answer
Kastor and Mobius are both strong choices, but they fit different needs. Choose Kastor if you mainly need building multi-step research assistants that delegate subtasks to specialized sub-agents — its edge is completely free and open-source with no licensing fees or usage limits. Choose Mobius if you need retail traders who want to automate a rules-based strategy without writing any code — its edge is removes the coding barrier entirely, making algorithmic trading accessible to non-technical users. Kastor starts at Free; Mobius starts at Approximately $29/month for expanded strategy limits and live trading.
Features compared
- Multi-agent orchestration framework for coordinating multiple AI agents simultaneously
- Open-source codebase with full transparency and community-driven development
- Extensible architecture supporting custom LLM backends and tool integrations
- Agent communication and context-sharing protocols for collaborative task execution
- Natural language strategy builder that converts plain-English trade descriptions into executable algorithms
- Automated backtesting engine that evaluates strategy performance against historical market data
- Live and paper trading execution so users can deploy or simulate strategies in real market conditions
- AI-assisted refinement that suggests improvements based on backtest results and risk metrics
Pros & cons
- Completely free and open-source with no licensing fees or usage limits
- Gives developers full control over agent logic, memory, and integrations
- Active open-source community enables rapid iteration and community-contributed extensions
- Requires developer expertise to set up and configure compared to managed platforms
- Documentation and support may be limited compared to commercial multi-agent frameworks
- Removes the coding barrier entirely, making algorithmic trading accessible to non-technical users
- End-to-end workflow from idea to backtest to live execution in a single platform
- Fast iteration cycle allows users to test many strategy variations in a short amount of time
- Backtest results may not fully capture slippage, fees, or liquidity constraints in live markets
- Reliance on natural language input means complex or highly specific strategies may require multiple refinements to build accurately
The verdict
Choose Kastor if
you mainly need to building multi-step research assistants that delegate subtasks to specialized sub-agents. Its edge: completely free and open-source with no licensing fees or usage limits.
Choose Mobius if
you mainly need to retail traders who want to automate a rules-based strategy without writing any code. Its edge: removes the coding barrier entirely, making algorithmic trading accessible to non-technical users.
Frequently asked questions
Is Kastor better than Mobius?
Neither is universally better. Kastor is stronger for building multi-step research assistants that delegate subtasks to specialized sub-agents, with an edge in completely free and open-source with no licensing fees or usage limits. Mobius is stronger for retail traders who want to automate a rules-based strategy without writing any code, with an edge in removes the coding barrier entirely, making algorithmic trading accessible to non-technical users. Pick based on your main task.
Which is cheaper, Kastor or Mobius?
Kastor starts at Free and Mobius starts at Approximately $29/month for expanded strategy limits and live trading. Free tier: Kastor — Fully free and open-source; Mobius — Limited strategy builds and backtests available at no cost.
What is Kastor best for?
Kastor is best for building multi-step research assistants that delegate subtasks to specialized sub-agents, automating complex workflows where multiple ai agents must collaborate and hand off results, prototyping agentic pipelines for startups or research teams without incurring api or platform costs.
What is Mobius best for?
Mobius is best for retail traders who want to automate a rules-based strategy without writing any code, finance students and hobbyists exploring quantitative trading concepts through hands-on experimentation, active investors looking to quickly prototype and stress-test multiple strategy ideas before deployment.
Do Kastor and Mobius have free plans?
Kastor: Fully free and open-source. Mobius: Limited strategy builds and backtests available at no cost. Check each tool's pricing page for current limits, as plans change.