The Most Famous Advice in Investing Comes From a Man Who Ignores It.

The most repeated piece of investing advice in the world is simple. Buy everything, spread it out, stop trying to pick winners. And the most famous messenger of that advice has spent about sixty years doing the exact opposite, holding a handful of companies, enormous positions, for decades at a time. I'm talking about Warren Buffett. He tells regular investors to own a broad index fund, and he built his own fortune the opposite way. He has even said that most of the money he leaves for his wife should go into a low-cost S&P 500 index fund.

The cheap read is do as I say, not as I do. The true read is better, and it's the whole lesson. His advice and his practice are answers to two different questions. Spreading out is what he recommends for people who won't make investing their life's work, which is nearly everyone, and concentrating is what a life's work looks like from the inside, decades of full-time attention riding on every position. Neither one is a lie. Advice always fits the life it was built for, even his.

So here's what spreading out actually is, because it never got explained where I grew up either. It isn't just owning many stocks. It's owning different kinds of things, different industries, different types entirely, some built to pay you now, some built to grow, some you can sell this afternoon, some that take years to walk away from. The point is simple. Set it up so no single company or industry can sink everything you own at once. And the trade is real too. Spread wide enough and no one thing can wreck you, and no one thing can make you either. Diversification buys survival, not fireworks.

Here's where I actually stand. For most people, in most situations, spreading out makes sense. Period. There are situations where concentrating might, and they're circumstantial, and the risk that rides along has to be understood going in, not discovered on the way down. Concentration has minted windfalls, and I've watched it do that. It has also unmade retirements, sent people back to work in their sixties, pushed the finish line out by a decade. One position, two possible endings, and it swings harder in both directions than a spread-out portfolio usually will.

There's a shape I see up close that threads it. A base that's spread out and sized to fund the life, the boring part, the part that has to work. And only past that line, the concentrated piece, usually the company stock that's been building for years. The base is what helps make the bet survivable, because if the concentrated part goes wrong, the life can still be funded, and if it goes right, everything past funded gets bigger. The reverse order is the one that produces the bad stories, the bet first, the base someday.

And your concentration, if you have one, probably wasn't a decision at all. It's the employer stock that kept vesting while you were busy working, quarter after quarter, until one company became most of the picture, the same company that already pays your salary. Maybe it's exactly the bet you'd choose today, knowing everything you know. The only thing that matters is the word choose. So the question this letter leaves with you is short. Which parts of your money are spread out because you chose it, which parts are concentrated because you chose it, and which parts are just the way things drifted?

That word my childhood never even had a word for turned out to be the most personal one on the whole list. Spreading out is the tool anybody can hold. How much of it your life needs is the part only your life can answer.

Talk Friday.

— Mateo