What is dollar-cost averaging?

Buying a fixed amount at regular intervals instead of all at once.

Many exchanges support recurring buys that automate it. The approach spreads the price you pay across time; it does not reduce the risk that an asset falls in value. Someone buying $100 of an asset every Monday is dollar-cost averaging whether they call it that or not.

The common mistake is treating it as a strategy that improves returns. It does not. It changes when you are exposed and it removes the decision of when to buy, which is a behavioral benefit rather than a financial one. It also carries a cost most people never total up, because a recurring buy is usually priced as an instant buy rather than as an order on the book.

How it works

You fix an amount and an interval, and the number of units you receive floats with price. When the price is low, the same money buys more units, so the average price you paid per unit ends up below the average of the prices themselves. That arithmetic is real and it is the only mechanical claim the method supports.

Exchanges implement it in one of two ways, and they cost very different amounts:

Funding matters as much as the fee. A card deposit carries its own charge on every purchase, while a bank transfer is often free but slower, so people funding weekly by card pay the deposit cost 52 times a year.

Example

Illustrative figures. You buy $200 a month for four months at prices of $100, $80, $125, and $100 per unit. You receive 2.00, 2.50, 1.60, and 2.00 units, which is 8.10 units for $800. Your average cost is $98.77 per unit, below the $101.25 average of the four prices. Now add a 1.5% instant-buy margin on each purchase: you pay about $12 in total, and your effective average rises to roughly $100.25.

Why it matters when you buy

The fee route you choose matters more than the schedule, because a small percentage charged repeatedly compounds into real money over a year. Compare what each venue charges for scheduled purchases against its order-book rates at the fee comparison, and check whether the asset has enough depth for regular small orders at the liquidity pages.

Related terms

instant buy — how most recurring buys are actually filled, spread — the hidden cost in a quoted price, maker taker fee — what an order-book buy costs instead, cost basis — what each purchase records for tax, tax lot — why many small buys mean many lots, volatility — the price movement being averaged over.

Questions

Does dollar-cost averaging reduce risk?

It reduces the risk of committing everything at a single price, and it does not reduce the risk that the asset falls. Money you have already invested is exposed exactly as it would be otherwise.

Do recurring buys complicate my taxes?

They create one tax lot per purchase, so a weekly plan produces 52 acquisition records a year, each with its own date and cost basis. That matters when you sell and have to identify which units went; see the tax pages.

Is it cheaper to buy weekly or monthly?

Fewer, larger purchases usually cost less where a flat fee or a per-deposit charge applies, because the fixed part is spread across more money. Where the cost is purely a percentage, the interval makes no difference to the fee.