Dollar-Cost Averaging: What It Does and Doesn't Do

Setting aside the same amount from each paycheck and putting it into the same fund or stock is the most common method among individual investors. It's called dollar-cost averaging, or DCA. Two claims are made about it at once: "it reduces risk" and "it boosts returns." The first is partly true; the second is largely false.

The Mechanism: Fixed Amount, Changing Share Count

The whole math of the method fits in one sentence: a fixed amount buys more shares in cheap months and fewer in expensive ones. So the average cost you pay is always below or equal to the simple average of the prices in those months.

The example shows the method's best case: a price that falls first, then recovers. The method's value lies exactly along that path.

What It Doesn't Do

It doesn't raise expected returns. In a market that rises over the long run, keeping part of your money in cash for months means giving up the return of that waiting period. In a 2012 Vanguard study using US, UK and Australian data, investing a lump sum all at once beat spreading it over twelve months in about two thirds of cases.

It doesn't fix a bad pick. Buying a stock that keeps falling on a schedule means putting more money into a sinking thing every month. The average cost falls, but if the company isn't recovering, a lower average means nothing. The method makes sense for a broad asset believed to rise over the long run; it doesn't change a company's fate. More: Index Fund or Single Stock?

It doesn't prevent losses. If the market goes sideways or down for ten years, the regular buyer loses too; just more slowly.

Its Real Job: Handing the Decision to the Calendar

DCA's real value lies not in the math but in behavior. "Should I go in now, or wait a bit?" is the question investors get wrong most often, and DCA lets you never ask it. Sticking to the plan in a downturn instead of stopping in panic decides the method's entire benefit. More: Investor Psychology

For most people DCA isn't even a choice: savings arrive monthly with the paycheck, so investing happens monthly too. The question only really comes up with a lump sum (an inheritance, a bonus, a sale), and the answer is a trade-off between expected return and how much regret you can bear from going in all at once and getting caught by a drop right away.

Two Layers When Buying From Türkiye

Someone buying US stocks regularly from Türkiye is really buying two things on a schedule: dollars and the stock. The monthly conversion also builds an average cost in the exchange rate. The price is the currency spread and fixed fees paid separately on each small purchase. On small amounts a fixed trading fee is proportionally large, so purchase frequency has to be balanced against cost. If the amount is small, fractional shares make sure all of it gets invested.

Where You'll See It on This Site

The long ranges on the Compare screen (such as 5 years) show an asset's path through declines and recoveries; the shape of that path is what decides why regular buying gains value along the way.