
Senior Portfolio Manager
December 30, 2025
DIARY OF A PORTFOLIO MANAGER
“In business, I look for economic castles protected by unbreachable 'moats'."
- Warren Buffett
Here we are, wrapping up 2025 and heading in to 2026. I am off to Toronto next week for the 2026 edition of RBC’s “Portfolio Management Conference”. Three days of chats and presentations. I will share notes from that in my next missive to you. For today, though, I have a question:
What Is an Economic Moat?
Some companies seem to have an uncanny ability to fend off rivals and maintain their market dominance year after year. This phenomenon, known as an "economic moat," doesn't just keep rivals at bay but also seems to separate successful firms from those that fail.
The term was first popularized by legendary investor Warren Buffett and it's perhaps his favorite metaphor. He’s used it in dozens of investor talks going back decades. "Economic moat" draws an evocative parallel with the water-filled trenches that protected medieval castles. In the business world, these moats characterize sustainable competitive advantages that shield a company's profits from marauding competitors.
If you and I decide to go into business together and become determined to start a cell phone network, Bell and Telus would hardly be worried. Where would we even begin to make a dent in their existing network? Same goes with CP and CN Rail if we opted to start a railway enterprise instead.
The Morningstar Economic Moat Rating
One of the external tools that we use is Morningstar and their intrinsic value calculations. They also have an Economic Moat Rating.
Morningstar identified five sources that build and widen a moat:
If we can expect a company’s competitive advantage to last more than 20 years, we consider it as having a wide moat. If it can fend off rivals for 10 years, it has a narrow moat. If a competitive advantage doesn’t exist or may prove fleeting, there’s no moat.
When searching for undervalued companies, those with narrow or wide economic moats often offer attractive return potential. The Morningstar Economic Moat Rating can help us identify those companies to provide superior long-term returns.
Perhaps, down the road, I will share some insights from Morningstar and their fair value estimates and how we make use of those. My guess is that you can’t wait.
In the meantime, I hope that you have a very Happy New Year!

This information is not investment advice and should be used only in conjunction with a discussion with your RBC Dominion Securities Inc. Investment Advisor. This will ensure that your own circumstances have been considered properly and that action is taken on the latest available information. The information contained herein has been obtained from sources believed to be reliable at the time obtained but neither RBC Dominion Securities Inc. nor its employees, agents, or information suppliers can guarantee its accuracy or completeness. This report is not and under no circumstances is to be construed as an offer to sell or the solicitation of an offer to buy any securities.