PERSONAL FINANCE / EVIDENCE INTO PRACTICE

Dollar-Cost Averaging: A Lower Average Price Can Still Mean a Loss

Work through dollar-cost averaging in a falling market. Separate contributions, average purchase price and returns before trusting a recovery chart.

By Mika vs Guru · 6 October 2026 · 4 minute read

General education, not individual investment advice. Capital is at risk; examples are hypothetical. Read the disclaimer.

The account balance keeps rising because you keep adding money. The investment itself is still losing. This is the first trap to remove when judging a dollar-cost averaging chart, especially one that starts at a market peak and ends with a triumphant recovery.

Dollar-cost averaging means investing equal amounts at regular intervals regardless of market movements. At lower prices the same amount buys more units; at higher prices it buys fewer. That is the mechanism described by Investor.gov. It is not a guarantee of profit. [SEC Investor.gov: Dollar Cost Averaging]

Three purchases, one uncomfortable result

Invented example, using dollars and fractional units: you invest $100 at a price of $100, another $100 at $80, and a third $100 at $50. You buy 1, 1.25 and 2 units, respectively. Total contributions are $300 and total units are 4.25.

Your average purchase cost is $300 ÷ 4.25, about $70.59 per unit. This is not the arithmetic average of the three quoted prices. You bought different numbers of units at each price, so cost divided by total units is the useful calculation.

At the final $50 price, the holding is worth 4.25 × $50 = $212.50. You have contributed $300 and are $87.50 below that amount. The lower average price is real. So is the loss. Describing only the first fact would hide the decision you actually face.

Recovery depends on what happens next

If the price later reaches $75, the same units are worth $318.75, before costs, distributions and taxes. If it instead falls to $40, they are worth $170. Neither path is implied by the purchasing schedule. The asset still has to produce the outcome.

The contribution-relative gain in the $75 scenario is $18.75 ÷ $300 = 6.25%. That is not an annualised return, and it does not adjust for the different dates on which the contributions entered. Label the measure rather than calling it simply “performance.”

Regular salary contributions and staging a lump sum are different decisions

If $100 becomes available each month, investing it regularly is a cash-flow plan. If $1,200 is already available and you choose to invest $100 monthly, you are also choosing to leave part of that capital uninvested for a period.

FINRA discusses the tradeoff: spreading an available lump sum can reduce exposure to an immediate drop, while keeping money out of a rising market can forgo gains. The right comparison includes the uninvested cash, its return and when it became available. [FINRA: The Benefits and Limitations of Dollar-Cost Averaging]

Do not compare an all-in portfolio with a staged portfolio by showing only the staged portfolio’s invested slice. Count the whole starting amount on both sides. Otherwise the chart quietly changes the resources being compared.

How to interrogate a “worst possible start” backtest

Our channel’s QQQ episode raises a useful question about starting at an unfavourable time. This article’s examples are not a reproduction of that historical test and do not claim its exact result. To reproduce a test, you need the actual data and assumptions.

Record the purchase dates, amount per contribution, price convention, reinvestment of distributions, costs, currency and endpoint. Ask whether the asset was chosen with knowledge that it later survived or recovered. Test a different end date and check a genuinely different asset, rather than only shifting the start within one eventual winner.

Also distinguish a declining diversified fund from a single company whose prospects have deteriorated. Repeated purchasing does not make those situations equivalent. The diversification guide examines concentration separately from purchase timing.

The four-column check to keep

For each period, write cumulative contributions, total units, current value and value minus contributions. Add costs and distributions as separate fields where relevant. This simple ledger prevents new deposits from masquerading as investment gains.

Then write what would interrupt the schedule: a changed cash need, a product change, or a revision to the reason for holding the asset. A plan that assumes you can always contribute through a downturn needs to account for the possibility that your income changes at the same time. The useful promise of a schedule is a repeatable action. It cannot promise a market recovery date.

Prepared with AI assistance for the Mika vs Guru publishing team. This is not a claim of professional accreditation or independent peer review. How we research, label examples and handle corrections.