Dollar Cost Averaging: A Boring Strategy That Actually Works

What Is Dollar Cost Averaging?

Dollar cost averaging (DCA) means investing a fixed dollar amount at regular intervals — regardless of what the market is doing. $500 on the 1st of every month, whether stocks are at all-time highs or in a correction.

When prices are high, your $500 buys fewer shares. When prices are low, your $500 buys more shares. Over time, this averages out your purchase price and removes the impossible task of timing the market.

A Real Example

Say you invest $200 per month in VTI over 6 months:

Month	VTI Price	Shares Bought	Total Invested	Total Shares
January	$220	0.91	$200	0.91
February	$210	0.95	$400	1.86
March	$195	1.03	$600	2.89
April	$185	1.08	$800	3.97
May	$200	1.00	$1,000	4.97
June	$215	0.93	$1,200	5.90

Your average cost per share: $203.39 — lower than 4 of the 6 months' prices. You automatically bought more when it was cheap and less when it was expensive, without making a single decision.

DCA vs Lump Sum: The Honest Truth

Here's where we have to be fair. Research from Vanguard shows that lump sum investing beats DCA about 67% of the time. If you have $12,000 and invest it all on January 1st, you'll statistically end up with more money than investing $1,000 per month over 12 months.

Why? Because markets go up more often than they go down. By waiting to invest, you miss out on returns during the months your cash is sitting on the sideline.

So Why Does Anyone Use DCA?

Three reasons:

1. Most people don't have a lump sum. If you're investing from each paycheck, you're dollar cost averaging by default. This isn't a strategy — it's just how saving works for most people.

2. Psychology matters more than math. Investing $50,000 on a Monday and watching it drop $5,000 by Friday is psychologically devastating — even if logically you know it'll recover. DCA protects you from the worst-case emotional scenario of going all-in at the top.

3. The 33% of the time lump sum loses, it loses big. When lump sum investing underperforms, it's usually because you invested right before a crash. DCA's underperformance is typically mild. DCA's worst case is better than lump sum's worst case.

When to Use Dollar Cost Averaging

• You earn a regular paycheck — Set up automatic investments from every paycheck. This is DCA by default and it's the right approach for almost everyone.
• You've received a windfall (inheritance, bonus, etc.) — If investing the entire amount at once would keep you up at night, spread it over 3-6 months. Yes, lump sum is statistically better, but only if you actually do it. A strategy you execute beats a strategy you abandon.
• Markets feel scary — If fear is preventing you from investing at all, DCA gives you permission to ease in gradually.

When NOT to Use Dollar Cost Averaging

• As an excuse to procrastinate — "I'll DCA into the market over the next 2 years" is often just fear dressed up as strategy. If you have money to invest and a long time horizon, shorter DCA periods (3-6 months max) are better than stretching it out.
• In retirement accounts with employer matching — If your employer matches your 401(k) contributions, contribute enough to get the full match immediately. Don't gradually ramp up and leave free money on the table.

How to Set Up DCA in 5 Minutes

1. Open a brokerage account (Fidelity, Schwab, or Vanguard)
2. Link your bank account
3. Set up automatic transfers — Pick an amount and a schedule (every paycheck, monthly, whatever)
4. Set up automatic investing — Tell the brokerage to automatically buy VTI (or your chosen fund) when the money arrives
5. Delete your brokerage app from your home screen — Seriously. Checking daily helps nothing.

The entire point of DCA is that you don't think about it. Set it up once and let compound interest do the work over decades.

The Bottom Line

Dollar cost averaging isn't the mathematically optimal strategy. It's the psychologically optimal strategy. And for real human beings with real emotions about money, psychology beats math every time.

The best investing strategy is the one you'll actually stick with for 30 years. For most people, that's automatic, consistent, boring DCA — and there's absolutely nothing wrong with that.