Why long-term investing works

Compounding is what happens when the return on your money also starts earning a return. Year 1, you grow 7%. Year 2, you grow 7% on the bigger pile. Year 30, you're growing 7% on a pile that is many times bigger than what you started with.

The curve looks almost flat for the first few years and then turns nearly vertical. Most of the magic happens late — which is why most people miss it.

A simple shortcut: at ~7% per year, money doubles roughly every 10 years. At 10%, every 7. $10,000 invested at 7% becomes $80,000 in 30 years — without adding a single dollar.

The first doubling feels slow. The second feels normal. The third and fourth feel like magic. That's the whole game.

Cash in a checking account doesn't sit still — it shrinks. At ~3% inflation (roughly the long-term US average), $100 today buys about $74 worth of stuff in 10 years, and around $41 in 30 years.

This is why "just keep it in cash" isn't safe for long horizons. The number on the screen doesn't change. But the things you can buy with it quietly shrink.

The textbook chart shows a smooth line going up and to the right. Reality is much bumpier. Stocks dropped 50% in 2008, 35% in March 2020, 25% in 2022. The line trends up over decades — but the year-to-year path is jagged.

The drops feel personal. Anyone telling you long-term investing is comfortable hasn't lived through enough of them.

The math is simple. The behavior is hard. Your brain says "sell" in March 2020 even though the math says "hold or buy more". The news rewards doing something; the math rewards doing nothing.

The investors who win at long-term aren't smarter — they sit through the bad years without flinching. That's the whole edge.

Multi-decade studies (DALBAR, Morningstar) keep finding the same thing: the typical active investor underperforms the broad market by several percent per year — almost entirely because they buy and sell at the wrong times.

Compounding + time + not selling at the wrong moment is the whole strategy. Everything else is decoration. The decoration is fun — but the compounding does the work.