Warren Buffett has openly called his takeover of Berkshire Hathaway itself — the company whose name now represents one of the greatest investment records in history — his worst trade ever.
The pain: Berkshire was originally a struggling textile mill. When its management offered to buy back Buffett's shares at a price slightly lower than what he'd been verbally promised, Buffett felt disrespected — and, out of what he later admitted was spite, bought controlling ownership of the entire failing company instead of simply selling and walking away. He spent the next roughly two decades trying to make a dying textile business work, tying up capital that could have compounded far better elsewhere, before finally shutting the textile operations and using Berkshire purely as an investment vehicle.
The lesson: Buffett has been unusually honest that this decision was driven by ego and emotion, not analysis — and he estimates it cost him enormously in lost opportunity cost over the following decades. From this and other early mistakes, his philosophy sharpened into rules he's repeated for 60 years: stay within your circle of competence — only invest in businesses you genuinely understand; be <cite index="0-1">"fearful when others are greedy, and greedy when others are fearful"</cite>; and — with major influence from his partner Charlie Munger — shift from buying merely cheap businesses to buying wonderful businesses at a fair price, since a great business compounds value for you over decades, while a mediocre one merely limps along no matter how cheap you bought it.
Key Takeaway
Even legendary investors make emotionally-driven mistakes. Buffett's real edge wasn't avoiding every error — it was honestly naming his worst one and adjusting his entire framework because of it.
Think About It
Have you ever made a financial decision purely to prove a point or out of anger at someone — rather than because it was the objectively best choice?
Legend Lab — The Circle of Competence Check
List your last 5 investments or long-term positions. For each, honestly rate 1–5 how well you actually understand that business's revenue model. Notice if your worst-performing pick also has your lowest understanding score.