Most Investing Mistakes Are Not Analytical
It is more about how we think, react, and behave when uncertainty shows up. By Benjamin Tan.
Over time, I have come to realize that many of the biggest mistakes investors make—myself included—are not analytical. They are behavioral. They come from misalignment between who we are and how we invest.
Some people freeze, waiting for the “perfect” entry point.
Some overtrade, chasing momentum and narratives.
Some hold on too long, anchored to past decisions.
These are not failures of intelligence. They are patterns. And those patterns are often rooted in personality.
The Role of Self-Awareness
One useful way to think about this is through the lens of the Johari Window.
The framework divides self-awareness into four quadrants: what is known to self and others (“Arena”), what is hidden (“Mask”), what is blind (“Blind Spot”), and what is unknown (“Unconscious”). In investing, many costly mistakes sit in the Blind Spot quadrant—patterns that others may observe, but that we do not fully recognize in ourselves.
This is where self-awareness becomes practical, not abstract. The goal is not to eliminate bias entirely, but to surface it early enough to manage it.
How My Own Approach Evolved
This idea of correlating self-awareness with personal investing did not come to me all at once.
My own investing journey started from a more traditional place. I was trained in finance, spent years in banking, and initially approached investing through the lens of valuation and discipline. Over time, that framework evolved. Not because it was wrong, but because it was incomplete.
What changed was not just what I invested in, but how I understood myself as an investor.
The shift from value to growth was not purely intellectual. It reflected a broader evolution in how I think about risk, conviction, and time horizon. And in hindsight, personality played a larger role in that evolution than I initially recognized.
A Different Way to Think About Portfolio Strategy
My personal journey became the foundation of my book, Suit Yourself: A Portfolio Strategy for Every Personality Type:
The premise is simple: There is no one-size-fits-all investing strategy.
A portfolio that works for one person may fail for another, not because the idea is flawed, but because it does not fit how that person actually thinks and behaves.
In the book, I explore this through the Enneagram framework, using storytelling and pop culture to make the concepts more accessible. The goal is not to prescribe what to buy, but to help readers understand how their own tendencies shape their decisions.
At its core, the book focuses on three things:
Why investors sabotage themselves
How personality shapes investment decisions
How to align portfolios with identity
Lowering the Barrier to Entry
One piece of feedback I received recently stood out. A reader told me that the ideas only fully clicked once they started reading the book.
That was useful to hear. It is suggested that the biggest barrier is not disagreement, but entry.
Read the Preview Chapters
So I decided to remove that barrier.
I have shared two chapters of the book on my website. These include the introduction and a chapter on my own investing journey, where I discuss how my philosophy evolved and how personality influenced that process.
If you are curious about how psychology intersects with investing, you can read the preview here.
The Real Risk in Investing
Whether or not you decide to read further, the core idea is worth considering: Investing is not just about finding the right opportunities. It is about understanding the person making the decisions.
And that person is you.
My book, Suit Yourself: A Portfolio Strategy for Every Personality Type, blends Enneagram psychology, pop culture, and behavioral finance to offer a personalized roadmap to investing. It examines how personality biases unconsciously influence investing behaviors. Learn more at my author page or order the book on Amazon. Follow me on X.com (formerly Twitter) @ConsumeOwnTech and Yahoo Finance.
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