thesis-drift

Detects investment thesis drift by comparing evidence across dated research report snapshots.

16.4k|2.5k|Updated Apr 7, 2026
One-click install
npx skills add https://github.com/xbtlin/ai-berkshire --skill thesis-drift-xbtlin
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: thesis-drift
Source: https://github.com/xbtlin/ai-berkshire/tree/main/codex-skills/thesis-drift
Command: npx skills add https://github.com/xbtlin/ai-berkshire --skill thesis-drift-xbtlin

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Long-term investors struggle to distinguish real fundamental changes from mere rewording or price swings when reviewing their holdings. This Skill compares two versions of an investment thesis report and determines whether the underlying facts actually changed, preventing both overreaction to noise and blindness to genuine deterioration. ## Core Features & Use Cases - Evidence-Based Drift Detection: Compares valuation anchors, core assumptions, red lines, management quality, and competitive moat across two report snapshots, classifying each dimension as Improved, Unchanged, or Weakened. - Three Operating Modes: Supports explicit two-report comparison, automatic snapshot discovery in the reports directory, and graceful handling when no historical baseline exists. - Verified Numerics: Routes all valuation, percentage, and market-cap calculations through tools/financial_rigor.py to eliminate LLM arithmetic errors, with cross-source validation requirements. - Use Case: After a new earnings release, compare your original Pinduoduo thesis snapshot against an updated report to learn whether margin compression is a real thesis break or just a price-driven narrative shift, and get a migrated action recommendation (Buy/Hold/Reduce/Exit). ## Quick Start Ask the AI to run a thesis drift check on a company by providing its name along with the paths to the old and new thesis reports, or just the company name to auto-discover snapshots in the reports folder.

Frequently Asked Questions about thesis-drift

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I check if my investment thesis has changed?

Provide the company name plus paths to an old and new thesis report, or just the company name to auto-discover snapshots in the reports directory. The skill compares evidence across five fixed dimensions and reports whether the thesis drifted, improved, or stayed unchanged.

What is the difference between thesis drift and price movement?

Thesis drift means verifiable facts changed: revenue, margins, competitive position, management behavior, or red-line triggers. Price movement only affects the valuation anchor dimension and does not by itself change business quality, so the skill explicitly separates the two.

What happens if there is no historical baseline report?

The skill refuses to fabricate a baseline from memory and instead reports that drift detection is impossible. It directs you to first establish a structured thesis baseline with the thesis-tracker skill, then rerun drift detection after new evidence arrives.

How are valuation calculations verified during comparison?

All numeric work is delegated to the financial_rigor.py tool, including valuation verification, market-cap checks, cross-source validation, and three-scenario modeling. Key financial figures require at least two independent sources, and unverifiable numbers are flagged as low confidence.

Can reworded reports trigger a false drift signal?

No. The skill normalizes evidence into a comparison table and only judges facts, not phrasing. Synonymous rewrites, reordering, or tone changes without underlying data changes are classified as Unchanged, and Unchanged rows cite no fabricated evidence.