---
type: "Topics"
locale: "en"
url: "https://longbridge.com/en/topics/100000000939912.md"
description: "Here are some of the biggest mistakes I’ve made as an investor. 1/ Underestimating the competitive response to successful product introductions, leading me to extend current revenue and earnings growth into the future.  Most innovation is easily replicable.2/ Over-relying on management’s guidance or forecasts instead of doing my own 360 degree research - seeking input from customers, suppliers, competitors. 3/ Underestimating the power of brand leverage - extending powerful product franchises into new categories especially by competitors of a stock I own.4/ Underestimating cannibalization - incorrectly assessing the negative impact of new product intros on a company’s existing base of products.5/ Betting too much on a CEO’s abilities to turn around a franchise based on his/her past record of success.6/ Overpaying for a mature business or franchise.  I’ve rarely made money paying an outsized multiple relative to forward revenue or earnings growth (>4x PEG).7/ Ignoring repeated negative earnings revisions.  Sometimes a company misses numbers and earnings come down.  But if it’s a pattern that keeps repeating, beware.I try to incorporate these learnings into my current research disciplines so I don’t make the same mistakes over and over.  As an investor you’re doing well if you get 60% of your bets right.  With the 40% of bets I get wrong, I try to learn from them."
datetime: "2026-10-15T13:45:32.000Z"
locales:
  - [en](https://longbridge.com/en/topics/100000000939912.md)
  - [zh-CN](https://longbridge.com/zh-CN/topics/100000000939912.md)
  - [zh-HK](https://longbridge.com/zh-HK/topics/100000000939912.md)
author: "[Gary Black Tracker](https://longbridge.com/en/profiles/17077344.md)"
generator: "portal-rs"
---

# Here are some of the biggest mistakes I’ve made as…


---
> **Disclaimer: This article is for reference only and does not constitute any investment advice.**