Understanding Market Risk

Volatility is not risk

Volatility measures how much a price moves around. Risk is the chance of a permanent loss of capital, or of not having the money when you need it.

An equity fund that swings violently but is held for twenty years is volatile. Whether it is risky depends entirely on whether you can leave it alone for twenty years. The same fund, holding money you need in eighteen months, is genuinely risky, not because it moves more, but because you may be forced to sell during a fall.

Volatility becomes risk at the moment you are compelled to sell. Everything else is temporary discomfort.

The loss that actually matters

A fall in price is not a loss until it is realised or the underlying business is permanently impaired. There are three ways a temporary decline turns into a real one:

• You sell. Usually because the fall was larger than expected and the plan was made without honestly considering it.
• You are forced to sell. A medical emergency, a job loss, a business call on cash, arriving at the same time as the drawdown, which is not a coincidence, since recessions produce both.
• The asset does not recover. Individual companies fail permanently. Broad diversified indices historically have not, but individual stocks do it routinely.

Most of retail investing risk management is about preventing the second one, because it is the one you cannot argue yourself out of.

The risks worth naming

Market risk, the whole market falls. Diversification within equities does not help; asset allocation does.

Concentration risk, too much in one company, one sector, or one correlated bet. Employees holding large amounts of their employer's stock face this in a particularly acute form: their salary and their portfolio depend on the same firm.

Liquidity risk, you cannot sell at a fair price when you need to. More pronounced in small-cap stocks and certain debt instruments, which can be difficult to exit precisely when everyone wants out.

Credit risk, a borrower does not repay. Relevant to debt funds, which are frequently sold as "safe" without distinguishing between government securities and lower-rated corporate paper.

Inflation risk, the quiet one. Money in a savings account is nominally safe and loses purchasing power every year. Over a thirty-year retirement this is not a minor effect; at 6% inflation, prices roughly double every twelve years.

Behavioural risk, you are the risk. Buying after a rally, selling after a fall, and abandoning a plan at the worst moment destroys more household wealth than any market event.

Sequence-of-returns risk

This one deserves its own section because it is genuinely counter-intuitive and it matters enormously to anyone drawing down a portfolio.

While you are accumulating, the order of returns is largely irrelevant, the same set of annual returns in any order produces the same final value. Once you are withdrawing, order becomes critical.

Two retirees can experience an identical average return over twenty-five years. The one who suffers a severe fall in the first three years, while withdrawing, may run out of money. The one who gets those bad years at the end will not. Selling units during a drawdown to fund living expenses permanently removes capital that would otherwise have recovered.

The standard defence is a cash buffer, two or three years of expenses held outside equity, so that a bad market never forces a sale. The retirement calculator assumes a steady return and therefore does not model this; it is one of that tool's real limitations.

Tolerance versus capacity

Risk questionnaires usually measure tolerance, how you feel about losses. What matters at least as much is capacity, how much loss your circumstances can actually absorb.

A 28-year-old with stable income, no dependants and a thirty-year horizon has high capacity even if they are temperamentally nervous. A 58-year-old planning to retire in two years has low capacity regardless of how relaxed they feel about volatility.

When the two conflict, capacity should win. Feelings change with the market; a fixed date does not.

Managing it in practice

1. Match assets to horizons. Money needed within three years should not be in equity. This single rule prevents most forced selling.
2. Hold an emergency fund. Three to six months of expenses, accessible, separate from investments.
3. Diversify across asset classes, not just across scheme names. Six large-cap funds is one bet held six times.
4. Decide the rebalancing rule in advance, in writing, while calm, so the decision is already made when markets are not.
5. Size positions so no single failure is fatal. Particularly for direct equity and employer stock.
6. Insure the catastrophic things, so a health event does not become a portfolio event.