Risk and Volatility — Not the Same Thing

Volatility describes how much a value moves up and down over a period. It is measurable, it appears in the ratios printed on a fact sheet, and it says nothing about direction.

Risk, for a household, is the chance of not having the money you needed when you needed it. That definition is deliberately about you rather than about the investment, because the same holding poses different risks to different people.

Fifteen-year money in a volatile scheme is moving about a great deal and is not especially risky, because there is time for movement to pass. Two-year money in the same scheme is genuinely risky, because there is not. Nothing about the scheme changed between those two sentences.

Only under one condition: you sell while the value is down.

Until then a fall is a number on a statement. It becomes permanent the moment units are redeemed, which is why the same market decline is harmless for one household and expensive for another sitting next to it.

That happens for two reasons. Either the money was needed then, which is a planning failure rather than a market one, or the person could not tolerate watching it and sold. Our guide on what a red number actually means is about the second, and our page on when to sell covers deciding in advance.

Which means most of what people call market risk is really the risk of being forced to sell, and that is a risk you can manage without predicting anything.

This is the part the word volatility hides entirely, and it is where households are most often exposed without knowing.

Purchasing power. A holding that never falls can still buy less each year. There is no statement anywhere that shows this, which is exactly why it persists, and our page on inflation and your savings covers it.

Not being able to reach the money. Property cannot be sold in a week and a lock-in does not care about your emergency. Both are real risks that produce no visible movement at all.

Credit. In a lending arrangement the risk is that the borrower does not pay, which does not appear gradually. It appears at once, as our page on debt funds sets out.

Concentration. Everything you own responding to the same conditions is a risk regardless of how smooth each holding looks individually.

A fact sheet carries volatility measures and a riskometer, and both are useful within limits.

The ratios describe how the scheme moved over a chosen past period. They are backward-looking by construction, and a stretch of calm produces reassuring figures right up until conditions change. Our page on the fact sheet covers where they sit.

The riskometer places a scheme on a fixed scale at category level, which our page on the riskometer explains. It is a comparison between schemes rather than a statement about what could happen to your money.

Neither knows your horizon, your buffer or your other holdings, which are the three things that decide whether a scheme is risky for you.

Worth naming plainly, because it is the largest one in most households and never appears in any document.

A portfolio you abandon halfway is worse than a more modest one held throughout. So your own tolerance is part of the arrangement rather than a soft consideration, and the honest measure of it is not how you describe yourself.

It is what you actually did the last time something you owned went down. That single fact predicts outcomes better than any ratio, and it is why we ask it rather than asking how somebody rates their risk appetite.

Somebody who sold in the last fall should hold a smaller equity share held with conviction. That is not a lesser plan, it is a plan that matches the person, and our page on asset allocation is where that judgement gets applied.

Confusing the words produces two errors, and households make one or the other rather than avoiding both.

Treating movement as danger. Somebody who equates volatility with risk keeps thirty-year money somewhere that never moves, and spends three decades paying an invisible cost to avoid a visible one. That is the more common error in this state, and it is why our page on inflation exists.

Treating stability as safety. The reverse error is assuming that anything which does not move about is fine for any purpose. A holding with no visible movement can carry credit risk, or be impossible to convert when needed, and both arrive suddenly rather than gradually.

The first error is the more expensive of the two over long periods, because the mechanism our page on compounding describes needs time and never gets it.

The correction for both is the same, and it is not a view about markets. Decide what each pot of money is for and when it is needed, and the appropriate amount of movement follows from that rather than from how movement makes you feel.

Four things, and none of them requires a view on markets.

• Match money to dates. Nothing needed within about three years should be somewhere it can be lower on the day.
• Keep a buffer so an ordinary emergency never forces a sale, as building an emergency fund sets out.
• Spread across things that do not move together, which our page on portfolio overlap shows how to check.
• Size the equity share to what you will actually hold through a bad stretch, not to what you would like to be able to hold.

Do those and most of what people mean by risk has been dealt with, without anybody forecasting anything. If you want to work through your own position, get in touch.