What is pound cost averaging?
Investing a fixed amount at regular intervals — say £100 every month — regardless of what the market is doing. Some months you'll buy when prices are high, some when they're low. Over time, the average cost per unit smooths out. It's the opposite of trying to "buy the dip" — and far easier to stick to.
A simple example
Invest £100/month into a fund over three months:
- Month 1 — price £10 per unit → you buy 10 units
- Month 2 — price drops to £5 per unit → you buy 20 units
- Month 3 — price recovers to £8 per unit → you buy 12.5 units
After 3 months you've invested £300 and own 42.5 units. Average price paid: £7.06 — lower than the starting price of £10, because you automatically bought more when prices fell. That's pound cost averaging doing its job.
"When markets fall, pound cost averaging turns bad news into an opportunity — you simply buy more for the same money."
Why it works psychologically
Market crashes are scary. Many investors panic and sell — locking in losses — then miss the recovery. PCA removes the temptation to react emotionally. You invest the same amount every month, market up or down. It runs on autopilot. There's no decision to make, which means there's no wrong decision to make.
The best way to do it in the UK
Set up a regular monthly direct debit into a Stocks & Shares ISA. Most platforms let you automate this so it buys your chosen fund each month without you having to do anything:
- Vanguard — simplest option, very low fees, ideal for beginners
- Fidelity — wide fund selection, good for larger portfolios
- Hargreaves Lansdown — most popular in the UK, excellent app and research tools
Pick your platform, choose a global index tracker fund, set the monthly amount, and leave it alone.
The key takeaway
The best investment strategy is one you can stick to. Investing £200/month consistently for 20 years beats investing £2,400 once a year when you remember. Set it up, automate it, let time do the work.