Key Questions Asked by the Duan Yongping Master Perspective: The 9-Point Framework

The Duan Yongping master perspective codifies nine essential questions—from business quality and moat durability to management integrity and valuation discipline—that drive every investment decision in the ai-berkshire repository’s dyp-ask skill.

The xbtlin/ai-berkshire repository implements the investment philosophy of Duan Yongping (段永平) through a structured decision-making engine called dyp-ask. Defined in skills/dyp-ask.md, this framework distills Duan’s value-investing approach into a repeatable hierarchy of "core thoughts" and "frameworks" that analyze everything from business models to corporate culture, rendered in his distinctive first-person voice using classic phrases like "买股票就是买公司" (buying stocks is buying companies) and "本分" (principled integrity).

The Nine Core Questions of the Duan Yongping Framework

The Duan Yongping master perspective is built around nine non-negotiable questions that guide every analysis, from quick investment checks to deep-dive company research. These questions are encoded in skills/dyp-ask.md and executed sequentially when the skill is invoked.

1. What Is the Business?

Duan stresses that a "great business" is the starting point for any investment. This question asks whether the company’s core offering creates a durable, repeatable cash-flow engine that can sustain long-term value creation. According to the source code in skills/dyp-ask.md (lines 17-27), if the business itself is not great, no amount of cheap valuation can save the investment.

2. What Is the Business Model?

Beyond identifying the business, Duan evaluates whether the model exhibits four must-have traits: differentiation, a moat, pricing power, and low-asset intensity. As defined in lines 30-36 of skills/dyp-ask.md, businesses lacking these structural advantages fail the business-model test regardless of current profitability.

3. Who Runs the Company?

Management assessment focuses on whether leaders are "本分" (principled), aligned with shareholders, and capable of long-term execution. The framework in skills/dyp-ask.md (lines 103-108) rejects companies where management lacks integrity or demonstrates poor capital allocation, regardless of operational excellence.

4. Is the Company Inside My Ability Circle?

Duan’s "能力圈" (ability circle) rule limits investment to companies you can comprehensively comprehend. Lines 62-70 of skills/dyp-ask.md mandate that investors must truly understand the company’s products, markets, and competitive risks before committing capital. Violations trigger the "看不懂就不买" (don’t buy what you don’t understand) response.

5. What Is the Valuation?

Valuation is treated as a "毛估估" (rough estimate) of future cash-flows. According to lines 73-78 of skills/dyp-ask.md, the price must be below intrinsic value to be attractive, but precision is less important than ensuring a significant margin of safety. Duan prefers "好公司便宜的时候买" (buy good companies when they're cheap).

6. What Is the Corporate Culture?

Culture is viewed as a core moat that cannot be captured on the balance sheet but drives sustainable advantage. Lines 88-96 of skills/dyp-ask.md examine whether the company embodies "本分", user-orientation, and long-term focus. Toxic or short-term cultures disqualify investments immediately.

7. What Is the Investment Mindset?

This question examines the investor’s own readiness: Do you possess the patience, discipline, and "平常心" (steady mind) to hold the stock for years? Lines 22-30 of skills/dyp-ask.md emphasize that without the psychological fortitude to "封仓十年" (seal the position for ten years), even the best analysis fails in execution.

8. What Are the "Stop-Doing" Rules?

The "Stop-doing list" enumerates actions that must be avoided to preserve capital and integrity. As coded in lines 43-52 of skills/dyp-ask.md, these include no margin trading, no shorting, and no buying outside your ability circle. Any violation of these hard constraints triggers an automatic rejection.

9. What Are the Macro Considerations?

Duan explicitly states he does not chase macro-economic forecasts. Lines 12-19 of skills/dyp-ask.md establish that good businesses succeed regardless of short-term macro swings, making GDP predictions or interest rate bets irrelevant to the investment decision.

Technical Implementation in skills/dyp-ask.md

The Duan Yongping framework is not merely documentation—it is executable logic. The file skills/dyp-ask.md serves as the source of truth, defining the question hierarchy and Duan’s distinctive linguistic patterns (direct, concise, and peppered with his classic catch-phrases).

When parsed by the ai-berkshire engine, the skill maps user queries onto the nine-question framework above. A separate Codex-compatible version is auto-generated at codex-skills/dyp-ask/SKILL.md, allowing the perspective to function within Claude-Code and Codex environments as described in AGENTS.md.

Invoking the Duan Yongping Perspective

You can activate this framework by calling the dyp-ask skill with a JSON payload. The engine parses the query, maps it to the appropriate question blocks, and returns answers in Duan’s first-person voice.

Ask a pure investment question:

{
  "skill": "dyp-ask",
  "prompt": "Should I buy Tencent today?"
}

The model runs through all nine core questions—business quality, business model, management, ability-circle, valuation, culture, mindset, stop-doing list, and macro view—ending with a "看不懂就不买" verdict if any rule is violated.

Ask a business-model analysis:

{
  "skill": "dyp-ask",
  "prompt": "What makes the C2M model so valuable?"
}

This invocation focuses specifically on the business-model section (differentiation, moat, pricing power, asset lightness) and ties the analysis back to Duan’s principle of buying good companies when they're cheap.

Summary

The Duan Yongping master perspective in ai-berkshire provides a rigid, repeatable framework for value investing:

• Nine core questions cover business quality, model durability, management integrity, circle of competence, valuation discipline, cultural moats, psychological readiness, prohibitions, and macro-agnosticism.
• Hard constraints via the Stop-doing list automatically disqualify investments involving margin, shorting, or incomprehensible businesses.
• Executable logic resides in skills/dyp-ask.md, with auto-generated Codex compatibility at codex-skills/dyp-ask/SKILL.md.
• Linguistic authenticity ensures responses reflect Duan’s actual voice, using terms like "本分", "毛估估", and "能力圈".

Frequently Asked Questions

What does "ability circle" (能力圈) mean in the Duan Yongping framework?

The ability circle is Duan’s principle of limiting investments to businesses you can truly understand. According to skills/dyp-ask.md (lines 62-70), if you cannot explain the company’s products, competitive position, and risks in simple terms, the investment falls outside your circle and must be rejected regardless of potential returns.

How does the dyp-ask skill treat macroeconomic analysis?

The framework explicitly ignores macroeconomic forecasting. Lines 12-19 of skills/dyp-ask.md state that good businesses succeed regardless of GDP trends or interest rate swings, so the nine questions focus entirely on company-specific factors rather than economic predictions.

Where is the Duan Yongping perspective implemented in the codebase?

The primary implementation is in skills/dyp-ask.md, which defines the full question hierarchy and linguistic style. This file is referenced in README_EN.md as one of four value-investing masters, while AGENTS.md explains how the skill integrates with the repository’s Claude-Code compatibility layer. A generated Codex version exists at codex-skills/dyp-ask/SKILL.md.

What is "毛估估" (rough estimate) in Duan’s valuation approach?

"毛估估" represents Duan’s insistence on approximate valuation rather than precise spreadsheet modeling. As defined in lines 73-78 of skills/dyp-ask.md, this means estimating future cash flows roughly to ensure the price offers a clear margin of safety, rather than optimizing for decimal-point accuracy in DCF models.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}