The Complete Guide to Dollar-Cost Averaging in 2026

Dollar-cost averaging (DCA) — the practice of investing a fixed dollar amount at regular intervals regardless of market conditions — is often dismissed as simplistic. But a growing body of research suggests it is not just simple but genuinely optimal for most retail investors, primarily because it removes the emotional element from investment decisions.

The mathematics of DCA are straightforward. When prices are high, your fixed dollar amount buys fewer shares. When prices are low, it buys more. Over time, this produces an average cost per share that is lower than the average share price over the same period — a mathematical property called the arithmetic-geometric inequality.

DCA in Volatile Markets

DCA is particularly valuable during periods of high volatility, which tend to be when investors make their worst decisions. During the 2022 bear market, investors who maintained their DCA programs and purchased shares at depressed prices generated returns of 40-60% on those specific purchases within 18 months as markets recovered. Those who paused contributions during the downturn missed those gains entirely.