Dollar-cost averaging
What is Dollar-cost averaging?
Dollar-cost averaging invests a fixed money amount at regular intervals regardless of short-term market price.
Platforms should distinguish automatic investing of new income from deliberately holding an available lump sum in cash. Both involve periodic purchases, but only the latter carries an explicit timing choice and cash opportunity cost. Backtests should include interest, fees, taxes, and the predetermined schedule without hindsight changes.
The schedule reduces timing regret but cannot prevent loss or guarantee a favorable average purchase price.
If a scheduled purchase fails, the policy should define whether it is retried, skipped, or added to the next installment.
How it works
A fixed contribution buys more units when price is lower and fewer when price is higher. Payroll retirement contributions are a common example. The method automates behavior and removes repeated timing decisions, but does not guarantee profit, prevent loss, or ensure the eventual average price is below the future market price.
New savings versus existing cash
Regularly investing income as it becomes available does not necessarily delay investment. Deliberately phasing an already available lump sum holds part in cash and reduces market exposure during the schedule. Because risky assets generally have positive expected return, that delay often has opportunity cost, though it can reduce short-term downside and regret.
Behavioral benefits
A predetermined schedule can reduce paralysis, FOMO, recency-driven timing, and emotional reaction to volatility. It can help an investor begin and remain consistent. If the investor abandons purchases after declines or accelerates after rallies, the method becomes discretionary timing. Automation and adequate emergency liquidity support adherence.
Costs and implementation
Frequent small trades can create commissions, spreads, conversion cost, tax lots, and operational complexity, although many platforms reduce explicit charges. Minimums and fractional-share availability matter. Allocation can drift if contributions go only to one asset. Directing new cash toward underweight holdings can combine averaging with cost-aware rebalancing.
Practical choice
Define total amount, dates, frequency, instruments, cash yield, stop date, and response to market closure before starting. Compare with immediate investment under several paths, including loss and rapid rally. Select the approach the investor can complete. Do not market averaging as a way to buy at the bottom or eliminate market risk.
Also known as: DCA
Sources and further reading
- Dollar Cost Averaging, Investor.gov, U.S. Securities and Exchange Commission
- Ten Things to Consider Before You Make Investing Decisions, Investor.gov, U.S. Securities and Exchange Commission