Contract

• Input: problem description and inputs defined by the skill body.
• Output: Markdown artifact with completed process steps.
• Side effects: none.
• Dependencies: none.
• Stop condition: all process steps executed; artifact saved with required sections.
• Risk: low.
• Boundary: produces reasoning artifact only; no system changes.

Portfolio Theory

Apply Modern Portfolio Theory — efficient frontier, CAPM, APT, performance attribution — with explicit assumptions and regime analysis.

When to use