Warren Buffett’s Only Rule: Don’t Lose Money. Here’s the Math Behind It.
This month, the Nasdaq had its worst day in over a year — down more than 4% in a single session, as a chip-stock sell-off erased upward of a trillion dollars of market value in an afternoon. Days like that are exactly why the most famous rule in investing is also the most ignored. Stone tablet carved with Warren Buffett's Rule No. 1: never lose money “Rule No. 1: Never lose money. Rule No. 2: Never forget Rule No. 1.” Warren Buffett has said this so many times it sounds like a bumper sticker. People nod, smile, and then immediately go buy a 3x leveraged ETF or dump their savings into a meme coin at the top. The rule sounds obvious. It is not obvious. It is mathematics — and the math is brutal. This post is about one thing: why avoiding large losses matters more than chasing large gains, and why the numbers prove it. The Recovery Table Nobody Wants to See When you lose money, you don’t just need to make it back. You need to make back more than you lost — and the gap gets exponentia...