Lump-sum investing vs. dollar-cost averaging

Lump-sum investing puts available money to work at once; dollar-cost averaging invests equal portions at regular intervals regardless of market movement. Investing $12,000 immediately gives all $12,000 market exposure on day one, while investing $1,000 monthly for 12 months leaves some money uninvested until later dates.

What lump sum vs dollar cost averaging means

Dollar-cost averaging is investing equal amounts at regular intervals, while a lump sum is one investment of the available amount at one time. A dollar-cost-averaging calculator illustrates repeated purchases; this choice compares the timing of investing a sum already available.

Lump-sum investing vs. dollar-cost averaging: worked example

With $12,000 available, one plan buys immediately at $100 per share and receives 120 shares. A second plan invests $1,000 at prices of $100, $80, and $120 in its first three months, buying 10, 12.5, and 8.333 shares. The schedule can lower or raise the average purchase price depending on the path; it does not remove market risk or guarantee a better result.

How to calculate lump sum vs dollar cost averaging

For a lump sum, shares equal the full amount divided by executed price. For periodic investing, add shares bought in each period and divide total cash by total shares for the average cost. Compare the dates during which cash is exposed to the market and the dates it remains cash.

Use the relevant inputs with these related Calculatort pages: dollar-cost-average tool · investment-return calculator · average share-cost model.

Read the numbers before making a decision

Available amount check 1. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 1 when it examines available amount at $12,000, lump-sum price at $100 per share, and lump-sum shares at 120. Identify the unit for available amount in pass 1 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 1, recording the changed available amount makes the result traceable rather than a headline number.

Lump-sum price check 2. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 2 when it examines lump-sum price at $100 per share, lump-sum shares at 120, and periodic amount at $1,000 monthly. Identify the unit for lump-sum price in pass 2 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 2, recording the changed lump-sum price makes the result traceable rather than a headline number.

Lump-sum shares check 3. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 3 when it examines lump-sum shares at 120, periodic amount at $1,000 monthly, and example prices at $100, $80, $120. Identify the unit for lump-sum shares in pass 3 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 3, recording the changed lump-sum shares makes the result traceable rather than a headline number.

Periodic amount check 4. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 4 when it examines periodic amount at $1,000 monthly, example prices at $100, $80, $120, and available amount at $12,000. Identify the unit for periodic amount in pass 4 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 4, recording the changed periodic amount makes the result traceable rather than a headline number.

Example prices check 5. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 5 when it examines example prices at $100, $80, $120, available amount at $12,000, and lump-sum price at $100 per share. Identify the unit for example prices in pass 5 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 5, recording the changed example prices makes the result traceable rather than a headline number.

Available amount check 6. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 6 when it examines available amount at $12,000, lump-sum price at $100 per share, and lump-sum shares at 120. Identify the unit for available amount in pass 6 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 6, recording the changed available amount makes the result traceable rather than a headline number.

Lump-sum price check 7. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 7 when it examines lump-sum price at $100 per share, lump-sum shares at 120, and periodic amount at $1,000 monthly. Identify the unit for lump-sum price in pass 7 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 7, recording the changed lump-sum price makes the result traceable rather than a headline number.

Lump-sum shares check 8. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 8 when it examines lump-sum shares at 120, periodic amount at $1,000 monthly, and example prices at $100, $80, $120. Identify the unit for lump-sum shares in pass 8 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 8, recording the changed lump-sum shares makes the result traceable rather than a headline number.

Periodic amount check 9. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 9 when it examines periodic amount at $1,000 monthly, example prices at $100, $80, $120, and available amount at $12,000. Identify the unit for periodic amount in pass 9 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 9, recording the changed periodic amount makes the result traceable rather than a headline number.

Example prices check 10. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 10 when it examines example prices at $100, $80, $120, available amount at $12,000, and lump-sum price at $100 per share. Identify the unit for example prices in pass 10 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 10, recording the changed example prices makes the result traceable rather than a headline number.

Available amount check 11. A contribution-timing comparison marks when each dollar becomes exposed to market movement; the same total contribution can therefore have a different experience on pass 11 when it examines available amount at $12,000, lump-sum price at $100 per share, and lump-sum shares at 120. Identify the unit for available amount in pass 11 before changing a number: dollars, shares, months, a percentage, or a tax category. In check 11, recording the changed available amount makes the result traceable rather than a headline number.

Common mistakes

Do not call a monthly payroll contribution a delayed lump sum, use the arithmetic average of prices as the average cost, assume a schedule protects against loss, or compare strategies over different end dates.

Where this calculation stops

Cash yield, fees, taxes, account rules, future prices, liquidity needs, and the investor's ability to stay with a plan are outside the three-price illustration.

Source and verification

Investor.gov defines dollar-cost averaging as investing equal portions at regular intervals regardless of market ups and downs. Read the named source. For this illustration, verify the source date and the controlling record for available amount before relying on the result.