DCA vs. Lump Sum: Comparing Outcomes Across Market Paths
Whether to invest a windfall all at once (lump sum) or spread it out in equal monthly chunks (dollar-cost averaging, or DCA) is one of the oldest debates in investing. In theory, if markets trend steadily upward, putting your money to work as early as possible with a lump sum wins. But real markets rise and fall, and during volatile stretches, DCA's habit of buying more shares when prices are low and fewer when prices are high can lower your average cost — sometimes enough to come out ahead.
This simulator generates a new random monthly return path based on the expected annual return and volatility you enter, then calculates the final value of both a lump-sum strategy and a DCA strategy along that same path. The lump-sum strategy invests the full amount on day one and lets it compound; the DCA strategy splits the total evenly across the investment period. Click "Run Simulation" a few times and you'll see firsthand how the winner can flip even under identical assumptions, simply because the market path changed.
Each result is just one randomly generated hypothetical scenario and doesn't guarantee any real investment outcome. Run the simulation repeatedly to get a feel for the range of possibilities, and choose the approach that best matches your risk tolerance and cash-flow needs.
Frequently Asked Questions
When markets trend steadily upward, investing a lump sum early often wins. When markets are volatile or decline for a stretch, spreading purchases out with DCA can lower your average cost and come out ahead — the outcome depends on the market path.
This simulator generates a new random monthly return path each time, based on the average return and volatility you entered. Since real markets are also unpredictable, it's worth running it several times to see the range of possible outcomes.