Dollar-Cost Averaging: What Regular Investing Can and Cannot Do

Choose the contribution and schedule first

For example, an investor might contribute a fixed amount after each paycheck. The schedule determines when new money is invested instead of requiring a fresh prediction about whether this week is a market low.

The investment still needs to fit the purpose of the money. Regular purchases of a concentrated or highly risky asset remain concentrated or highly risky. A contribution schedule is one part of a plan, separate from selecting the assets and deciding when the money will be needed.

Sources: Investor.gov: Dollar-cost averaging

Follow the share count through three purchases

Assume three $120 purchases with no fees or distributions. At prices of $30, $20, and $40, the purchases acquire four, six, and three shares. The total is thirteen shares for $360.

The average cost is $360 divided by thirteen, about $27.69 per share. It is not the simple average of the three quoted prices, which is $30, because more shares were bought at the lower price. This example illustrates the arithmetic, not a forecast of market behavior.

Check the value after buying, too

If the market price later falls to $25, the thirteen shares are worth $325. That is $35 less than the $360 contributed, before any fees or taxes. Buying more shares at low prices does not ensure that the next price will be higher.

Costs can also affect a small recurring plan. If each purchase carries a fee, calculate the total across the year and ask whether the account offers a lower-cost way to implement the same intended investments.

Sources: FINRA: Benefits and limitations of dollar-cost averaging

Distinguish new earnings from cash waiting to be invested

Investing part of each paycheck uses money as it becomes available. Splitting an existing lump sum over future dates means some of that money waits in cash. These are different starting situations.

Gradual investment of a lump sum changes exposure to near-term price movements. If prices rise while money waits, it can miss gains; if prices fall, later purchases may be cheaper. Compare that tradeoff with your time horizon and tolerance for losses, without assuming one schedule will win in every market.

1. Define the goal and suitable investments.
2. Choose an affordable contribution schedule.
3. Check transaction and account costs.
4. Review the plan without treating short-term prices as a scorecard.

Sources: FINRA: Benefits and limitations of dollar-cost averaging