Dollar-cost averaging (DCA) means investing a fixed amount on a regular schedule regardless of market conditions. When prices are low you buy more shares; when high, fewer. Over time this reduces the average cost per share and eliminates the need to time the market. It’s the strategy behind 401(k) payroll contributions.

A common rule of thumb is to invest 15–20% of gross income. At minimum, contribute enough to capture your full employer 401(k) match (free money). After that, max your Roth IRA ($7,000/year in 2026 if under 50), then return to the 401(k). For taxable accounts, invest any additional surplus.