Invest It All at Once, or Spread It Out?
Every possible starting day in the S&P 500 since 1927 — 24,747 of them — run through the same question: is it better to invest a lump sum all at once, or spread it out gradually over a fixed period? Pick an amount and a time window below to see what actually happened, historically, across nearly a century of markets.
Does the answer change with how long you invest for?
Investing it all at once wins more often the longer the time window — but by a smaller margin each additional year, since a longer window also gives markets more time to recover from a bad entry point either way.
The real reason to spread it out: a smoother ride
Investing all at once usually wins on the final number. But it also means being fully exposed from day one — if a downturn hits early, you feel the whole thing. Spreading the money out means less is at risk early on.
When does spreading it out actually win?
The single biggest factor historically hasn't been luck — it's where the market already was when you started. Grouped by how far the market was running above or below its own recent trend at the moment of investing: