Should you pause dollar-cost averaging when the market is falling?

Pausing during a fall skips the months when each dollar buys the most shares, which is where the method does its work. If the falling market has changed your plans, such as needing the money sooner, revisit the target mix on a calm day. A scary headline alone is a poor reason to stop the schedule.

How often should you invest when dollar-cost averaging?

Match the schedule to when the money arrives. For most people that means each payday or once a month. More frequent purchases smooth the average cost a little more, but each trade may carry a cost, so check your broker's fee schedule and pick a rhythm you can keep for years.

Is putting part of every paycheck into a retirement plan dollar-cost averaging?

Yes. A fixed contribution taken from each paycheck and invested on the same schedule is the same method, just done for you. The comparison with a lump sum only arises when you already hold a large amount of cash and must choose whether to invest it at once or spread it out.

Dollar-Cost Averaging Through a Full Market Cycle

Q: Dollar-Cost Averaging Through a Full Market Cycle

Investing a fixed amount on a schedule buys more shares when prices are low and fewer when they are high, so your average cost lands below the average price you paid across the cycle. That suits a beginner who cannot time the cycle. In a market that rises steadily, investing a lump sum at the start ends ahead.

Put $500 into a hypothetical stock fund every month for six months while its price goes $50, $40, $25, $25, $40 and back to $50, and you finish with 85 shares at an average cost of $35.29. Dollar-cost averaging through a market cycle works like that: because the dollar amount never changes, each purchase picks up extra shares in the cheap months and fewer in the dear ones, so a fall and a recovery leave you ahead even though the price ends where it began. It cannot guarantee a better result. In a steadily rising market, a lump sum invested at the start wins.

Why does a fixed sum buy more at the lows?

The dollar amount stays put. The price moves. At $50 your $500 buys 10 shares. At $25 the same $500 buys 20.

Cheap months add a lot of shares to the pile, dear months add few, and so the shares you end up holding are tilted toward the prices you would most like to have paid, which pulls your average cost per share below the simple average of the prices on the dates you bought.

You never have to find the bottom, or even know whether one is coming. Each purchase happens because the date arrived.

What happens across the full cycle?

Here is the hypothetical cycle month by month.

Now compare that cost with the prices themselves. Add the six prices and divide by six: $230 / 6 = $38.33. Your average cost of $35.29 sits below that, because the two $25 months bought twice as many shares as the $50 months did.

Fractional shares make the 12.5 possible. Where your account only buys whole shares, the leftover cash rolls into the next month and the arithmetic shifts by a few cents.

How does it compare with investing everything at the start?

Take the same $3,000 and put it all in during month one at $50. That buys 60 shares. Six months later the price is back at $50.

The price made a round trip. The lump sum rode it down and back up and ended flat. The schedule bought most heavily on the way through the trough, and that is where all of the $1,250 came from.

Where does the advantage disappear?

In a market that just keeps rising. Run the same $500 a month through prices of $25, $25, $40, $40, $50 and $50, a steady climb with no dip at all.

Look at the share count. The schedule ends with the same 85 shares as in the round trip, since it met the same six prices, only in a different order. The lump sum, by contrast, depends entirely on the price on day one, and a low price on day one followed by a steady rise is the case where spreading the money out costs you, here $1,750 of ending value. Nobody knows in advance which shape the next six months will take.

The method controls two things. Timing risk is the chance that you put everything in on the worst possible day. Regret is what makes people abandon a plan after that day arrives. Dollar-cost averaging trims both, and it gives you a reason to keep buying in the months when buying feels worst, which is when the next purchase has the most effect on your average cost.

Who is it for?

A beginner who cannot time the cycle, which describes nearly everyone who is honest about it. If your money arrives monthly from a paycheck, you are already doing it, and the lump-sum question never comes up. The question matters only when you hold a pile of cash, say from a bonus or an inheritance, and must choose between one order and a series of them.

Pick the amount once. Pick the date once. Then automate it, because a purchase that needs your approval each month is one you will hesitate over in exactly the months when the price is lowest and the headlines are worst, and those are the months that do the most for your average cost.

A schedule also pairs well with the target mix and rebalancing band in investing through market cycles. New money goes in on schedule. The band handles drift. Neither asks you to name the stage of the cycle, and if you want a record of conditions anyway, the market cycle indicators checklist shows how to adjust the size of new purchases from rules you set in advance.

What can go wrong?

Stopping is the big one. A schedule that pauses during the fall skips the months that would have bought 20 shares for $500 and keeps the months that bought 10, so the average cost drifts up toward the highest prices.

Choosing a schedule longer than the money can wait is another. Spreading a lump sum over many months leaves cash idle, and the longer the stretch, the more a rising market costs you. The swings themselves cost something too, and the viewpoint on smoother returns works through why a portfolio that falls less can end ahead.

If you are still sorting out which savings belong in stocks at all, start with Mise en Place for Money, or browse the full list of free courses first.