Dollar-Cost Averaging: How It Works and When It Helps

Dollar-cost averaging (DCA) means investing the same amount of money at regular intervals, such as $300 every month, no matter what the market is doing. If you contribute to a 401(k) from each paycheck, you're already doing it.

How it works

Because you invest a fixed dollar amount, you automatically buy more shares when prices are low and fewer when prices are high. Here's a simple three-month example investing $300 each month:

• Month 1: price $50, you buy 6 shares
• Month 2: price $40, you buy 7.5 shares
• Month 3: price $60, you buy 5 shares

You invested $900 and own 18.5 shares, an average cost of about $48.65 per share, slightly below the $50 average price over the period. Try your own numbers in the dollar-cost averaging calculator.

The real benefits

• It removes timing decisions. Nobody can reliably predict short-term market moves. DCA means you never have to.
• It builds a habit. Automatic monthly investing is one of the most reliable ways to grow wealth over decades.
• It softens regret. If the market drops right after you start, you're buying the dip with your next contribution rather than watching a lump sum fall.

DCA vs. investing a lump sum

If you already have a large sum to invest, putting it all in at once has historically come out ahead more often than spreading it out. Studies of US and other markets have found lump-sum investing beat DCA roughly two-thirds of the time over the following 10 years, simply because markets rise more often than they fall and money waiting in cash misses those gains.

DCA still makes sense if spreading the money out is what lets you invest at all, or if a sharp drop right after investing everything would cause you to sell in a panic. For most people investing from each paycheck, the question never comes up: DCA is just how they invest.

How to start

1. Pick an amount you can invest every month without touching your emergency fund.
2. Choose a broad, low-cost fund, such as one tracking the S&P 500. See ETFs vs. mutual funds.
3. Set up automatic transfers and purchases with your broker. Many brokers support recurring investments and fractional shares.
4. Leave it alone, and increase the amount when your income rises.

To see what steady monthly investing can grow into, use the compound interest calculator.

This article is educational and not investment advice.

Frequently asked questions

Is dollar-cost averaging better than investing a lump sum?

Historically, investing a lump sum right away has come out ahead more often, because markets rise more often than they fall. Dollar-cost averaging can reduce regret and is the natural approach for people investing from each paycheck.

How often should I dollar-cost average?

Monthly or every payday is common. The schedule matters less than sticking to it consistently.

Does dollar-cost averaging work with ETFs?

Yes. Many brokers support automatic recurring purchases of ETFs, often with fractional shares, which makes investing a fixed dollar amount easy.