process
Know what you own
The rule
Never invest in anything you cannot explain in one sentence. If you cannot say what the business does and why you hold it, you do not own it; it owns you.
Where it flips
A simple story you can tell is not the same as a full one. 'I understand it' can be false confidence. A tidy one-line reason sometimes hides risks you never learned to look for.
Lynch's test is simple: you should be able to explain, in a couple of plain sentences a child would follow, what a company does, how it makes money, and why you own the share. If you cannot, you are not investing, you are gambling on a ticker. This holds for a whole mutual fund (know what it holds), for a company that just listed (module 002), and for a corporate action landing in your account. A split or bonus you do not understand can scare you into a bad move. Hold nothing you cannot describe, because understanding is what lets you hold through a fall.
A worked example
An investor holds a share purely on a tip and panics when it drops, having no idea what the company does. A neighbour who can explain the business in one sentence calmly holds through the same dip. [illustrative]
How to spot it
- ·you can explain the business in one plain sentence
- ·you have a stated reason for owning each holding
- ·you hold nothing purely on a tip or ticker
Peter Lynch · One Up on Wall Street