Investing
DCA buys a fixed dollar amount on a schedule. It lowers timing regret. Historically, investing a lump sum as soon as you have it usually wins — because markets rise more months than they fall.
Updated 2026-09-08 · 8 min read
Dollar-cost averaging is a rule: invest a fixed dollar amount on a calendar regardless of the headline. You buy more shares when prices are down and fewer when they are up. The rule's job is to remove the question 'is this a good day?'
Payroll 401(k) contributions are DCA by default. That is the useful version. The version people argue about is a pile of cash already sitting in checking — a bonus, a house sale, an inheritance — dribbled in over a year.
If expected returns are positive, cash that waits earns less than cash that is invested. Spreading a lump sum over twelve months means about half of it sits in cash for half a year. That drag is why lump sum wins in most historical windows.
DCA still has a job: it is a commitment device. A plan you will follow beats a theoretically better plan you abandon after a 12% week.
Paycheck money: automatic every payday into a target-date or broad index fund. Bonus cash: invest as soon as the emergency fund and high-APR debt are handled. If the number is large enough to keep you up, split it across 3–6 months and park the waiting cash in T-bills or HYSA.
Do not confuse DCA with waiting for a dip. Waiting is market timing with extra steps.
Run the numbers: compound interest calculator.
Not on average. Lump-sum investing outperforms DCA most of the time because the money spends more months in the market. DCA is insurance against a crash in month one, paid for by missing rallies.
If sitting on cash will make you freeze, a 3–6 month schedule is a reasonable behavioral patch. If you already invest every paycheck, you are already DCAing the cash that actually arrives on a schedule.
It lowers the average versus buying everything at the first peak. It also buys fewer shares when prices rise. Smoother path, usually less wealth.
Educational only. Verify IRS limits and loan quotes before acting.