Investment Research Report Writing Overlay

Investment Memo Craft

Purpose

Turn investment research into a decision-ready Codex research report. Keep the data discipline of the underlying research skill, but make the output easier for an investor to use: concrete business mechanics, sharp inverse thinking, explicit opportunity cost, action thresholds, and calm Markdown typography.

Use this as a writing and judgment overlay. It does not replace financial-data rules, primary-source checks, valuation tools, or report audit tooling.

For long-form AI Berkshire outputs, title the artifact as a "research report" by default. Use "investment memo" only when the user explicitly asks for a memo format.

This is a Codex-only hand-written skill kept under codex-skills/ for simple installation. Do not add a same-named skills/investment-memo-craft.md source unless intentionally adopting this workflow for Claude Code too.

Core Workflow

1. Open with context; reserve the full decision for after the evidence.

   • In the first screen, state the research date, price, market cap, valuation, and a short thesis.
   • Do not front-load the full buy/hold/sell table unless the user explicitly asks for an executive memo.
   • Put the detailed recommendation, investor-specific actions, and price bands near the end, after business quality, risk, and valuation have been argued.
   • Separate "good business" from "good investment at this price".

2. Build the operating map before the philosophy.

   • Include revenue structure, segment economics, unit drivers, and 3-5 year trends early.
   • For asset-heavy businesses, show the key assets individually when they explain the moat.
   • Explain the pricing mechanism, customer lock-in, cost structure, and reinvestment needs.

3. Compress business essence into one memorable sentence.

   • Prefer a sentence that describes who pays, why they pay, what is scarce, and what repeats.
   • Avoid generic labels such as "industry leader" unless followed by the mechanism that makes leadership durable.

4. Make the moat falsifiable.

   • Score or table the moat by source: brand/pricing power, switching cost, network effect, scale, cost advantage, regulation, resource scarcity, technology.
   • Explain whether the moat widened or narrowed over the last 5 years.
   • Ask what can destroy the moat, even if the answer is "not competitors, but regulation/weather/price paid".

5. Do real inverse thinking.

   • Include failure paths with probability, impact, and observable indicators.
   • Write the strongest bear case in language a smart short seller or non-buyer would actually use.
   • Explicitly identify the most likely analytical mistake.

6. Evaluate management through capital allocation.

   • Replace vague praise with decision history: acquisitions, divestitures, buybacks, dividends, leverage, reinvestment, strategic pivots.
   • Judge incentives: insider ownership, controlling shareholder behavior, compensation, related-party transactions, and shareholder return policy.
   • Ask whether the business depends on a person or on a system.

7. Connect industry trend to value capture.

   • Distinguish civilization-level trend from investable company-level economics.
   • Describe where the company sits in the value chain and who captures the profit pool.
   • Identify whether TAM growth, pricing, utilization, or capital intensity is the real driver.

8. Convert valuation into action.

   • Show current multiples, reverse DCF intuition, scenario valuation, historical comparison, and comparable companies when relevant.
   • Include dividends or capital returns in expected return when they matter.
   • Provide price bands, add signals, trim/sell signals, and what would change the thesis.

9. Close with a decision memo.

   • Include a summary table by business quality, moat, management, risk, trend, and valuation.
   • Give distinct advice for empty-handed investors and existing holders.
   • Include the action table here, not at the top, for long-form research reports.
   • End by separating AI analysis confidence from actual investment certainty.

Style Standards

• Prefer concrete numbers and mechanisms over adjectives.
• Use tables when they reduce cognitive load: assets, segments, failure paths, management decisions, scenario valuations, action bands.
• Write in clear investor prose. A good memo should be understandable after one read and useful after one month.
• Keep memorable formulations, but never let rhetoric outrun evidence.
• Avoid hiding behind vague labels such as "wait and see" without specifying the price or event that would change the recommendation.