Every investor would like to buy when prices are low and sell when they are high. Almost no one can do it consistently. Dollar-cost averaging is a strategy that gives up on trying. Instead of guessing the right moment, the investor puts in the same amount of money at regular intervals, whatever the market is doing.
How It Works
The method is simple. An investor chooses an amount, say $100, and a schedule, say once a month, and buys the same investment each time. Because the dollar amount is fixed, the number of shares changes. When the price is high, $100 buys fewer shares. When the price is low, it buys more. Most people with a workplace retirement plan already do this without using the name. A set amount comes out of each paycheck and goes into the same funds, month after month.
The Arithmetic
Suppose an investor puts in $100 a month for four months, and the share price is $20, then $10, then $10, then $20. The purchases are 5, 10, 10, and 5 shares, for a total of 30 shares at a cost of $400. The average price over the four months was $15, but the investor’s average cost per share is about $13.33. The gap exists because more shares were bought when they were cheap. The investor ends with holdings worth $600 even though the price finished exactly where it began.
Why People Use It
The main benefit is psychological. Investing a large sum just before a market drop is painful, and fear of that outcome keeps many people from investing at all. Spreading purchases over time removes the pressure of picking a single moment. It also builds discipline. An automatic schedule keeps an investor buying during downturns, when prices are low and the temptation to stop is strongest. Falling markets become an opportunity to accumulate shares instead of a reason to panic.
The Trade-Off
Dollar-cost averaging does not guarantee a profit or prevent losses. If prices fall steadily, the investor still loses money, only more slowly. For someone who already has a lump sum, such as an inheritance, the evidence leans the other way. Because markets rise more often than they fall, studies by fund companies have found that investing the full amount immediately has produced better results about two-thirds of the time. Spreading it out lowers the risk of bad timing at the cost of a lower expected return.
Conclusion
Dollar-cost averaging is less a way to beat the market than a way to stay in it. It replaces prediction with habit and makes volatility work, at least partly, in the investor’s favor. For anyone investing out of regular income, it is the natural approach. The amount and the schedule matter less than the consistency of sticking to them.