A few months ago, I stated that it’s a good idea to invest in the market in small bites over time, rather than diving in all at once. This method is called “dollar-cost averaging,” and it’s a popular strategy in personal finance circles.
But a widening body of evidence suggests that you should dive in headfirst instead of dipping your toes into the market.
The Background
Dollar-cost averaging supporters say that if you pour every dollar into the market at the same time, you might accidentally buy at the worst moment, when the price is peaking. If you buy stocks in small increments over time, though, you spread out your risk.For example, a person with $5,000 who wants to invest in The XYZ Index Fund might:
Invest the entire $5,000 on Jan 1 at a rate of $50/share. This is called “lump-sum” investing.
- OR –
Invest $1000 on Jan 1 at $50/share
Invest $1000 on Feb 1 at $53/share
Invest $1000 on March 1 at $46/share
Invest $1000 on April 1 at $48/share
Invest $1000 on May 1 at $48/share
Average cost per share? $49 dollars. You’ll also own more shares. The same $1,000 will buy you more shares when prices are low and fewer when prices are high.
Conventional wisdom says that this strategy — easing into the market — is the best way to invest.
After I wrote about this a few months ago, one Afford Anything reader brought some research to my attention. The research he encouraged me to read makes a compelling case that dollar-cost averaging might NOT be the best practice.


