Stocks always go up in the long run, right?
Over long periods, US stocks have grown far faster than prices. That's true, and it's why people say "invest for the long run". What they don't say is how long the long run can be.
That's how long someone who invested at the August 2000 peak waited to be back where they started, counting dividends and after inflation.
And that's the US, the most successful stock market of the last hundred years. Japan's stock market peaked in December 1989 and only climbed back to that level in February 2024. Thirty-four years.
Averages are made of great decades and lost ones, and nobody lives the average. You live one path, and it depends on when you start and when you need the money.
Timing isn't everything, though. Someone who kept putting in $100 a month through those same 13 years, instead of everything at the top, ended up about 60% ahead after inflation. Buying a little every month meant buying cheap when prices were down.
To be fairThe long run has worked out well in the US so far, bad decades included. The point isn't that stocks don't work. It's that "in the long run" is a promise about averages, not about your next ten years. Spreading your money, adding a bit regularly, and not investing what you'll need soon are what protect you.