The news media typically covers stock markets using one exceedingly simple frame: Market goes up, good! Market goes down, bad!
And this much is true: If you're in a stage of life when you are pulling money out of the market, like a retiree living off accumulated savings, a higher stock market is indeed great news. But some simple experiments with four hypothetical people show why that calculus is a lot more complicated for younger people. The key lesson: The dramatic runup in the American stock market over the last five years is actually bad news for many young adults who are just embarking on saving for retirement.