What Risk Actually Means in Investing
Volatility, drawdown, and permanent loss — three different things people lump together.
“Risk” in investing has three distinct meanings that the industry blurs together. Understanding the difference is the difference between sensible risk-taking and panic-selling at the bottom.
1. Volatility — the day-to-day wobble
Volatility is how much an investment's price swings around its average. It's measured by standard deviation. Global stocks have ~15–20% annual volatility — meaning in a typical year, returns can vary ±15% from the average.
Volatility is what most people call “risk”, but it's mostly noise. A 10% drop in October that recovers in November is volatility, not loss. If you don't sell, nothing happened to you.
Volatility only matters if (a) you need to sell during the dip, or (b) it scares you into selling. The first is a planning problem. The second is a behavioural one.
2. Drawdown — the worst peak-to-trough fall
Drawdown is the deepest fall from a previous high. Over the last century, global stock drawdowns have included:
• 2008 financial crisis: −55% peak-to-trough, recovered in ~4 years
• 2020 Covid crash: −34%, recovered in 5 months
• 2022 inflation reset: −25%, recovered in ~12 months
• 1929–1932 Great Depression: −89%, recovered in ~25 years
Drawdowns are the real test. Can you watch £100k turn into £45k for 18 months without selling? If not, you're holding too many stocks.
3. Permanent loss — the only one that truly matters
Permanent loss is when you don't get your money back. Examples:
• A single stock goes to zero (Lehman, Enron)
• Selling at the bottom of a crash and not buying back in
• Inflation eating cash savings over decades
• Fraud or scam (Bernie Madoff, FTX)
A diversified global stock index has never permanently impaired a buy-and-hold investor over a 20+ year horizon. The 1929 case looks bad, but reinvested dividends made the round-trip in ~7 years.
What makes risk acceptable
You can take more volatility/drawdown risk if:
• Time horizon is long — 10+ years gives recovery room
• Income is stable — steady job means you don't need to sell
• Cash buffer is solid — emergency fund means crashes don't force liquidation
• You can sleep through it — behavioural tolerance is real and varies
How to size your risk
Use our portfolio allocation calculator to see what specific drawdowns look like in £ and to test stock/bond mixes. The honest test: imagine your portfolio dropping 35% tomorrow. If you'd sell, hold less in stocks.
