Stay inside the circle of competence
The size of your circle of competence matters far less than knowing where its edge is. Most investing mistakes happen just outside it, doing something that looked easy from a distance.
Every investor has a circle of competence - the set of businesses they genuinely understand well enough to judge. What matters is not how large that circle is, but how honestly its edge is known. Most investing mistakes happen just outside the circle, doing something that looked simple from a distance and turned out to require knowledge that was not there.
The edge matters more than the size
A small circle, well understood, beats a large one full of things you half-know. There is no prize for having an opinion on every business; there is a large penalty for acting on a shallow one. Knowing where competence ends - and being willing to say 'this one is not for me' - is one of the most valuable and least practised disciplines in investing.
The circle can grow, slowly
The edge is not a fence forever. Competence expands with genuine work - reading, watching an industry over years, understanding how a new kind of business actually earns its returns. But it expands slowly and honestly, through study, not through the confidence that comes from a rising price. New areas are earned, not assumed.
Comfort is not the same as competence
It is worth distinguishing the two. Familiarity with a name, a sector everyone is discussing, or a stock that has treated you well can all feel like competence without being it. Real competence is the ability to explain how a business makes money, what could go wrong, and why it will endure - from your own understanding, not from consensus.
Got a question on what you have just read - on bottom-up research, quality investing, or the Category III AIF structure? Write directly to the office. These essays are general views only, not investment advice.
A research-led equity investor with over twenty years in the Indian markets. Designated Partner of Stonebridge Advisors LLP, Investment Manager of Anchor Rock Investment Fund - I, a SEBI-registered Category III AIF.