Windfall: invest it all now, or average it in?

You got $50,000. Lump sum puts everything to work today; dollar-cost averaging (DCA) spreads it out monthly to reduce timing risk. The math favors going all-in — this tool shows you exactly why, and when to ignore that.

Windfall amount ($)

DCA period (months)

Expected annual return (%)

Annual volatility (σ, %)

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Lump sum, expected value

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DCA, expected value

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Lump sum edge

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Odds lump sum wins

Which actually wins?

Historically lump sum wins about two-thirds of the time, because markets drift up: money in the market longer earns the expected return sooner. Studies (e.g., Vanguard, 2012–2022 data) consistently find ~67% of the time.

Why would anyone DCA then?

Psychology and regret minimization — if investing a lump sum risks staying up at night, DCA gets you invested while reducing the "I bought at the worst moment" feeling. It costs expected return to buy calm.

The math here

Expected lump-sum value = amount × (1 + r)^(m/12). DCA = the sum of monthly tranches invested for the remaining months, ≈ amount × avg growth of a half-period. Edge is their difference; the win probability comes from a normal model using your volatility input, and is a rough guide, not a guarantee.