Dollar-cost averaging (DCA).
A definition, in plain English — with the books that teach it.
What it means
Investing a fixed dollar amount at regular intervals (e.g., $500 monthly) regardless of share price. The discipline removes timing decisions from the equation — you buy more shares when prices are low and fewer when they're high, mechanically averaging your cost basis.
Example
If you invest $500/month for a year and the share price ranges from $40 to $60, you'll mathematically end up with a lower average cost than if you'd put $6,000 in at a single point. DCA's real value isn't the math — it's behavioral: it removes the 'should I buy now or wait for a dip?' anxiety that causes most beginner investors to sit on cash for months. John Bogle and Burton Malkiel both make the case that DCA + index funds beats almost all active strategies for most investors because the discipline survives downturns.
