What Is Dollar Cost Averaging?
Last updated: March 2026
Learn how dollar cost averaging works, why it reduces risk, and how to set it up for your ETF investments. This strategy is the foundation of successful long-term investing.
Step 1: Understand the Core Concept
Dollar cost averaging means investing a fixed amount of money at regular intervals regardless of what the market is doing. Instead of trying to invest a large lump sum at the perfect moment, you spread your purchases over time. For example, you invest two hundred dollars on the first of every month into VOO. When prices are high, your fixed amount buys fewer shares. When prices are low, that same amount buys more shares. Over time, this averages out your cost per share and removes the impossible task of trying to predict market movements. It is the strategy used by most financially successful ordinary investors.
Step 2: See Why Timing the Market Fails
Research consistently shows that even professional fund managers cannot reliably time the market. A famous study by Dalbar found that the average investor earned significantly less than the market because they bought high during euphoria and sold low during panic. Dollar cost averaging eliminates this behavioral trap entirely. You invest on a schedule, not based on emotions or headlines. Studies comparing lump sum investing to dollar cost averaging show that while lump sum investing wins slightly more often over very long periods, dollar cost averaging dramatically reduces the risk of investing a large amount right before a major downturn.
Step 3: Calculate Your Investment Amount
Determine how much you can invest each period. Start by reviewing your monthly income and expenses. A common guideline is to invest ten to fifteen percent of your gross income, but any amount is better than zero. If you can invest fifty dollars per month, start there. If you can invest five hundred, even better. The amount matters less than the consistency. Choose an amount that is sustainable for at least twelve months without causing financial stress. Factor in an emergency fund first, ensuring you have three to six months of expenses saved before committing heavily to investments.
Step 4: Choose Your Investment Frequency
The most common frequency is monthly because it aligns with how most people receive paychecks. However, you can also invest weekly, biweekly, or quarterly. More frequent investing provides slightly better dollar cost averaging effects because your purchases are spread across more price points. However, the difference is marginal. Monthly investing is simple, easy to automate, and works well for the vast majority of investors. Choose a frequency that matches your payroll schedule. If you are paid biweekly, consider investing every two weeks. The best frequency is the one you will actually stick with consistently.
Step 5: Select Your Target ETFs
For a dollar cost averaging strategy, choose ETFs you plan to hold for the long term. Broad market index ETFs like VTI, VOO, or SCHB are ideal because they provide diversification across hundreds of companies with extremely low expense ratios. You can dollar cost average into a single ETF or split your investment across two or three funds for additional diversification, such as a US stock ETF, an international stock ETF, and a bond ETF. Keep it simple. The fewer funds you use, the easier it is to maintain discipline and track your progress over time.
Step 6: Automate Your Investments
The final and most critical step is automation. Log into your brokerage account and navigate to the automatic investment or recurring purchase section. Set up a recurring buy order for your chosen ETF with the dollar amount and frequency you decided on. Link it to your bank account so funds transfer automatically. Once automation is running, your job is to let it work without interference. Do not pause it when the market drops. Do not increase it impulsively when the market surges. Consistency is the entire point. Review your automatic investment once a year and increase the amount as your income grows.
Pro Tips
- ✓Align your investment date with your payday so the money is invested before you can spend it.
- ✓Never pause your automatic investments during a market downturn because that is exactly when you get the best prices.
- ✓Increase your contribution amount by at least the rate of inflation each year to maintain your real purchasing power.
- ✓Consider dollar cost averaging into a target date fund if you want a completely hands-off approach.
- ✓Keep a simple spreadsheet tracking your monthly contributions to stay motivated by seeing your progress.
Common Mistakes to Avoid
- ✗Stopping contributions during market downturns, which defeats the entire purpose of the strategy.
- ✗Overthinking the exact day or time to invest each month when the specific date matters very little over the long run.
- ✗Setting the investment amount too high and then being forced to stop because of cash flow problems.
Recommended: This beginner-friendly ETF course on Udemy covers everything from ETF fundamentals to building a recession-proof portfolio in 7 days.
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