Circle Of Competence
Circle of competence is the boundary of what an investor can understand well enough to judge, size, and hold through uncertainty. E160.一个价值投资者的 20 年回顾：求积分，求胜率，求时间 frames it as an internal honesty problem: outsiders cannot easily disprove whether a manager truly understands a company, so the manager must avoid turning “outside my circle” into a convenient excuse.
139. 泡泡玛特和拼多多值得投资么？ adds ICE’s temperament boundary. Knowing one’s circle is not only knowing industries; it is also knowing whether one can play a short-term, long-term, active, or passive investing game without losing behavioral control.
Key Claims
- The circle of competence should guide capital allocation, not become a shield against studying missed opportunities.
- A stable investment framework can coexist with an expanding research boundary.
- Comfort zone and competence are related but different: a portfolio should sit near areas the manager understands, while research work should push the boundary outward.
- The practical question is whether an opportunity can become knowable with enough work, not only whether it is known today.
- EP80 与查理·芒格的跨时空对话：当眼睛失明时，我们看见什么？ adds the Munger-style complement: inversion and irreversible-error avoidance help define where apparent understanding is too weak.
- Episode 139 adds that AI can widen preparation, but it does not make an unsuitable investing game suitable for the user.
Connections
- Value Investing — long-horizon investing depends on business understanding.
- Business Moat — one of the main objects the investor must understand.
- Margin Of Safety — needed when understanding remains imperfect.
- Financial Statement Analysis — evidence-gathering tool for expanding the circle.
- Human Judgment Under AI and AI Investment Research — AI can widen preparation, but judgment responsibility stays with the investor.
- Charlie Munger and Warren Buffett — adjacent wiki references for staying within what can be understood.
- ICE, AI-Compressed Investment Research Advantage, and Behavioral Investing Biases — episode 139’s self-knowledge and AI-assisted-research extension.