Everyone knows you're supposed to "buy low, sell high." The problem is that nobody — not professional fund managers, not quant traders, not AI systems — can consistently predict where the low is. Dollar-cost averaging (DCA) is the strategy that sidesteps this problem entirely.
What Is Dollar-Cost Averaging?
DCA means investing a fixed amount at regular intervals, regardless of what the market is doing. Instead of trying to invest £10,000 at the perfect moment, you invest £500 every month for 20 months.
When prices are low, your £500 buys more shares. When prices are high, it buys fewer. Over time, your average cost per share is lower than the average price over the period — simply because you bought proportionally more when things were cheap.
A Simple Example
Say you invest £100/month into a stock over 5 months:
| Month | Price | Shares bought |
|---|---|---|
| 1 | £50 | 2.0 |
| 2 | £40 | 2.5 |
| 3 | £30 | 3.33 |
| 4 | £40 | 2.5 |
| 5 | £50 | 2.0 |
Total invested: £500. Total shares: 12.33. Average cost per share: £500 ÷ 12.33 = £40.55.
The average price over the period was (50+40+30+40+50)÷5 = £42. Your DCA average cost (£40.55) is lower than the average market price — because you automatically bought more when it was cheapest.
DCA vs Lump Sum
Research (including a classic Vanguard study) shows that lump-sum investing outperforms DCA roughly two-thirds of the time in rising markets — because money invested earlier compounds for longer. However:
- Most people don't have a lump sum available. They have a salary and invest monthly by necessity.
- In flat or declining markets, DCA wins clearly.
- DCA investors are less likely to panic-sell because they didn't dump everything in at once and watch it fall.
- The psychological benefit of DCA — removing the decision of "is now a good time?" — is genuinely valuable.
If you have a lump sum, investing it immediately generally wins mathematically. If you're investing regular income, DCA is the natural and effective approach.
Setting Up DCA
- Choose your asset — broad index funds, individual stocks, ETFs, or crypto. The more volatile the asset, the more DCA helps smooth your entry.
- Set your interval — monthly is common and aligns with salary cycles. Weekly can work for higher-volatility assets like crypto.
- Automate it — most brokers allow recurring purchases. Remove willpower from the equation.
- Don't stop during downturns — this is where DCA's power is greatest. Those months when everything looks terrible are when you're buying the most shares.
DCA and Signal-Based Investing
DCA and signal-based investing aren't mutually exclusive. A common approach:
- Use DCA as the base strategy for your core index fund holdings.
- Use signals for a smaller, actively managed allocation where you're trying to add alpha.
- When a strong BUY signal coincides with a dip in your DCA schedule, treat it as confirmation to continue (or slightly increase) that month's contribution.
Browse Indikators to see current and historical signals for the assets in your DCA portfolio — not to replace the strategy, but to stay informed about the companies you're regularly investing in.