Dollar cost averaging means investing a fixed amount on a fixed schedule, say the same sum every month, regardless of what prices are doing. It works in any currency; the name stuck from the dollar.
In short
- You buy more shares when prices are low and fewer when they are high, automatically.
- It removes the hardest decision in investing: when to start.
- It does not guarantee a profit or protect against a market that keeps falling.
- If you already have a lump sum, investing it at once has historically done better more often, but feels worse when markets drop.
How it works, with numbers
Say you invest 100 every month for five months into the same fund, while its price moves around.
| Month | Price | Amount invested | Units bought |
|---|---|---|---|
| 1 | 10.00 | 100 | 10.0 |
| 2 | 8.00 | 100 | 12.5 |
| 3 | 5.00 | 100 | 20.0 |
| 4 | 8.00 | 100 | 12.5 |
| 5 | 10.00 | 100 | 10.0 |
You invested 500 and bought 65 units. At the final price of 10.00 they are worth 650, a gain of thirty percent, even though the price only returned to where it started. The months when the price was low bought the most units.
A falling price is unpleasant to watch and useful to someone buying every month.
Why it suits most people
- Most people invest from income, a little at a time, so it matches how money actually arrives.
- It takes timing out of your hands. Nobody reliably knows the right day to buy.
- It builds a habit, and habits survive bad news better than decisions do.
When it is not the best choice
If you already hold a large sum, spreading it out over a year means part of it sits uninvested while markets, on average, rise. Studies across many markets have found that investing a lump sum at once has come out ahead more often than not. The trade is emotional: a lump sum invested the week before a fall is hard to live with. Spreading it out is a reasonable price to pay for sticking with the plan.
It also does not rescue a poor investment. Buying a little every month of a company in decline is still buying a company in decline.
Making it work
- Pick an amount you can keep investing in a bad month, not just a good one.
- Choose a date just after you are paid, so the money goes before it is spent.
- Use a broad fund or a small set of holdings you understand.
- Keep an emergency fund first, so you never have to sell to cover a bill. See why an emergency fund comes first.
TruVest’s practice account lets you try a monthly plan on real prices with virtual money before using your own.
Common questions
Is dollar cost averaging a good strategy?
For most people investing from their income, yes. It removes timing decisions and buys more when prices are low. It does not guarantee a profit.
How often should I invest?
Monthly is common because it matches pay. What matters most is that the schedule is one you can keep.
Is it better to invest a lump sum or spread it out?
Historically a lump sum invested at once has done better more often, but spreading it out can make it easier to stay invested through a fall.
Does dollar cost averaging work in a falling market?
It buys more units as prices fall, which helps when prices recover. If prices keep falling, you still lose money.