What dollar-cost averaging is
Dollar-cost averaging (DCA) means investing a fixed amount at regular intervals instead of all at once. When prices are high your money buys fewer shares; when prices are low it buys more. In India the same idea is called rupee-cost averaging, and it's what a SIP does automatically.
Worked example
Lump sum vs DCA: what history suggests
With a steadily rising market, investing a lump sum immediately tends to come out ahead, because more money is invested for longer. Studies of US market history have found lump-sum investing beat spreading it out in roughly two-thirds of periods. This calculator's steady-return model shows the same effect.
DCA's value is protection against regret: if the market falls soon after you invest, you'll have only part of your money in. For many people, that makes it easier to start and stay invested, which matters more than a small difference in expected return.
When to use each
- Money from your paycheck: you're naturally doing DCA, so keep it automatic.
- A windfall you're comfortable investing: a lump sum usually has the edge.
- A windfall that makes you nervous: spreading it over 3–12 months is a reasonable compromise.
Investing in India? Use the SIP calculator and lumpsum calculator, which follow Indian fund conventions.
Making DCA automatic
Most US brokerages let you schedule automatic investments into index funds or ETFs weekly, every two weeks or monthly. Matching the schedule to your paycheck makes the habit effortless. If you're averaging a windfall, set the end date in advance and stick to it rather than pausing whenever the market looks shaky.
Frequently asked questions
Does dollar-cost averaging reduce risk?
It reduces the risk of investing everything just before a fall, but it also means part of your money sits out of the market longer.
Is a SIP the same as dollar-cost averaging?
Yes. A SIP invests a fixed rupee amount every month, which is rupee-cost averaging.
Why does the lump sum win in this calculator?
The calculator assumes steady returns, so money invested earlier always grows more. Real markets are volatile, which is why DCA can win in some periods.