The investor's chief problem - and even his worst enemy - is likely to be himself.
What Is Dollar-Cost Averaging?
Dollar-cost averaging is embarrassingly simple: invest the same amount of money at regular intervals, regardless of what the market is doing.
No checking stock prices. No waiting for dips. No trying to predict the future. Just consistent, automatic investing.
Example DCA Schedule
Invest $500 into VTI on the 1st of every month. Market up? Invest $500. Market down 20%? Still invest $500. Market at all-time high? You guessed it - $500. The schedule never changes.
What does dollar-cost averaging require you to do?
How DCA Works in Practice
The magic of DCA is that you naturally buy more shares when prices are low and fewer when prices are high.
Example: $200/month Investment
| Month | Share Price | Shares Bought |
|---|---|---|
| January | $50 | 4.0 shares |
| February | $40 (dip!) | 5.0 shares |
| March | $33 (crash!) | 6.1 shares |
| April | $50 (recovery) | 4.0 shares |
Result: $800 invested → 19.1 shares → Average cost: $41.88/share
If you had invested $800 all in January at $50, you'd only have 16 shares!
When Prices Drop
Your fixed dollar amount buys MORE shares. You're automatically “buying the dip.”
When Prices Rise
Your fixed amount buys fewer shares, but your existing shares are worth more.
DCA vs. Lump Sum: The Truth
Let's be honest: mathematically, lump sum investing usually wins.
Vanguard research shows that investing a lump sum immediately beats DCA about 66% of the time. Why? Because markets trend upward over time. The sooner your money is invested, the more time it has to compound.
So Why Use DCA?
- Most people don't have a lump sum. You invest as you earn - that's DCA by default.
- Psychology matters. Investing $50K right before a 30% crash is psychologically devastating. DCA reduces regret.
- DCA beats waiting. If DCA gets you invested while “waiting for a dip” keeps you in cash, DCA wins.
Why might someone choose DCA over lump sum investing?
Setting Up DCA
The best DCA is the kind you don't have to think about. Automate it.
Steps to Automate DCA
- 1Choose your investment (total market index fund is great)
- 2Decide your amount (whatever you can consistently invest)
- 3Pick your frequency (monthly aligns with paychecks)
- 4Set up automatic recurring purchases in your brokerage
- 5Forget about it (seriously, stop checking daily)
Most brokerages (Fidelity, Schwab, Vanguard) let you set up recurring investments for free. Set it once, and your wealth builds automatically.
The Bottom Line
Dollar-cost averaging isn't about maximizing returns - it's about making investing actually happen.
The perfect strategy you never follow beats nothing. A good strategy you automate beats everything you keep putting off until “the right time.”
Next, we'll cover portfolio allocation - how to decide what percentage goes where.