I’ve always been suspicious of dollar-cost averaging, or DCA as it’s called. It just doesn’t seem like the wisest decision. I’ve always preferred lump sum investing.

Dollar-Cost Averaging vs. Lump Sum Investing

With DCA, rather than investing your cash all at once, you invest chunks of it over time. For example, you might invest $12,000 over the course of a year, $1,000 each month. In contrast, with lump sum investing, you’d put the full $12,000 to work right away.

The problem with DCA, as I see it, is that it depends on market timing.

With DCA, you’ll be better off only if the market declines while you’re investing your money. If the market goes up, you will wish you’d invested everything at once.

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Vanguard Study

Well, Vanguard released a study that (more or less) reached the same conclusion.

Called “Dollar-cost averaging just means taking risk later”, the study compared the historical performance of dollar-cost averaging with lump sum investing (LSI). The results?

Vanguard then provided the following explanation:

The study’s results are interesting because many promote dollar-cost averaging as the way to enter the market. Yet CNN published a piece on the downside of DCA, as did Market Watch.

The Vanguard report took it all a step further and actually put numbers into the mix.

The report examined the possible outcomes of two investors: one who invested each month for a year versus one who made a lump sum investment. Vanguard used rolling 10-year historical investment returns to see which option turned out better.

The conclusion was that lump sum investors come out on top 67% of the time versus just 33% for those using DCA.

The result was a 2.3% improvement using lump sum over dollar-cost averaging.

It’s important to note here that investing in a 401(k) each paycheck is a great option. While it looks a lot like dollar cost averaging, it’s really not.

The difference is that you are investing what you can each pay period. It’s not as if you are intentionally holding onto more money, waiting to invest it next month.

The Vanguard report made this clear:

Dollar-Cost Averaging & Behavioral Finance

Let’s put the math aside. There is one situation where dollar-cost averaging might be the best choice.

Imagine you’ve come into a lot of money. You may have received an inheritance or a pension payout. Or maybe you won the lottery. A lump sum investment could see your portfolio drop by 20% or more if you invest just before a bear market.

The result could be emotionally devastating. It might even affect the way you see investing for the rest of your life.

It was a point Paul Merriman brought up in a recent podcast. Here, it would be better to dollar-cost average into the market over, say, 12 months.

You may or may not be better of than lump sum investing. You would, however, lessen the effect of a major market downturn.

Related: How to Profit from a Stock Market Crash

So, which approach do you think is best?

Resource: How to Get Started Invest with Little Money

Check out my podcast on this topic, here:


  • Rob Berger

    Rob Berger is the founder of Dough Roller and the Dough Roller Money Podcast. A former securities law attorney and Forbes deputy editor, Rob is the author of the book Retire Before Mom and Dad. He educates independent investors on his YouTube channel and at RobBerger.com.