Warren Buffett’s Honest Confession: Why Getting Bigger Made Winning Harder

Most executives spend their annual letters to shareholders celebrating growth. Warren Buffett used his to warn investors about exactly what that growth would cost them.

“When we were working with capital of $20 million, an idea or business producing $1 million of profit added five percentage points to our return for the year. Now we need a $370 million idea (i.e., one contributing over $550 million of pre-tax profit) to achieve the same result.”

— Warren Buffett, Berkshire Hathaway Shareholder Letters

This came from Buffett’s 1991 chairman’s letter, a year in which Berkshire posted a $2.1 billion gain in net worth — nearly 40% growth. By any measure, it was a triumphant year. Yet Buffett opened by immediately tempering expectations, pointing out that Berkshire’s equity capital had swelled to $7.4 billion, making the kind of returns it had generated over the previous 27 years essentially impossible to repeat. He wasn’t being falsely modest. He was doing what his letters had always done: teaching investors how to think clearly about what the numbers actually meant.

The 1991 letter was part of a body of work that Buffett had been quietly building since 1977 — annual missives that functioned less as corporate filings and more as a crash course in business and investing, written in plain language and stripped of the self-serving spin that characterized most shareholder communications. Where other CEOs hid bad news in footnotes, Buffett surfaced it in the opening paragraphs. The uncomfortable truth he raised here — that success at scale becomes self-limiting — was not something most investors wanted to hear. But it was exactly what they needed to understand.

The insight cuts to something that trips up investors and founders alike: the assumption that a winning formula scales indefinitely. It doesn’t. A small fund can double on a single brilliant idea. A $100 billion fund cannot — the position sizes required to move the needle would distort the very markets the manager is trying to exploit. Buffett was honest enough to say this out loud about his own company, at a moment when most people would have been tempted to simply take the credit for a great year. That intellectual honesty is itself a competitive advantage, because it forces disciplined thinking about where real edge still exists — and where it has been eroded by size.

For anyone allocating capital — whether running a business, a portfolio, or a department — the lesson is the same: the metrics that proved you were winning early on may be the wrong metrics to track as you grow. The game changes. Recognizing that shift, rather than clinging to old benchmarks, is what separates managers who sustain performance from those who coast on a reputation built in a different era.

The Memo

• Audit your benchmarks as you scale. The return thresholds, deal sizes, and growth rates that defined early success may be misleading or irrelevant at your current size. Recalibrate what winning actually looks like now.

• Communicate constraints honestly. Buffett told shareholders the truth about Berkshire’s ceiling at the height of a great year. That transparency builds the kind of trust that survives the inevitable down years.

• Respect the math of scale. Before pursuing a new initiative, ask whether it is large enough to matter at your current size — and whether your size will prevent you from executing it effectively.