What Is Market Volatility and How Should You React?
Stock market volatility is normal and inevitable. Here's how UK investors should think about it — and what to actually do when markets fall.
What Is Market Volatility?
Market volatility refers to the degree to which asset prices fluctuate over time. High volatility means prices are moving dramatically up and down. Low volatility means prices are relatively stable. Volatility is often measured using the VIX index — sometimes called the fear index — which measures the expected volatility of the US stock market based on options pricing. Equity markets are inherently volatile: the FTSE 100 has experienced intraday swings of 5 per cent or more during periods of stress, and the broader stock market has fallen by 30 to 50 per cent or more during major bear markets.
Why Volatility Is Normal and Expected
Market volatility is not an aberration or a sign that something is fundamentally broken. It is the normal functioning of a market where millions of buyers and sellers continuously update their assessment of future corporate earnings, economic conditions, inflation, interest rates, geopolitics, and countless other factors. Every piece of new information — a central bank announcement, an earnings report, a geopolitical development — causes prices to adjust. Over long periods, this price discovery process results in markets broadly reflecting the underlying value of the economy's productive capacity.
Historical Market Falls: Perspective Matters
Every significant market crash in history has eventually been followed by recovery and new highs. The 2008 global financial crisis saw the UK stock market fall approximately 45 per cent from peak to trough. It recovered fully within five years. The Covid crash of 2020 saw global markets fall approximately 35 per cent in a matter of weeks — and recover to new highs within months. Even the most severe bear markets — when viewed over a sufficiently long time horizon — have proved to be temporary interruptions in a long-term upward trend in equity values.
The Emotional Trap: Panic Selling
The most damaging mistake most retail investors make is to sell their investments during a market downturn. This is psychologically understandable — watching your portfolio fall by 20 or 30 per cent is deeply uncomfortable, and the narrative that surrounds crashes ("the worst crisis in decades", "unprecedented market turmoil") makes it feel rational to get out. But selling during a crash locks in losses and means you miss the recovery. Numerous studies show that the average retail investor significantly underperforms the market index simply because they buy high during bull markets and sell low during bear markets.
What You Should Actually Do During a Market Fall
The correct response to a market downturn for a long-term investor is almost always to do nothing — or to invest more if possible. If you have a regular investment plan set up, continue it. Lower prices mean you are buying more units of your chosen fund for the same monthly contribution — this is the benefit of pound-cost averaging in action. If you have spare cash and a long time horizon, a market correction can be an excellent opportunity to invest at lower prices. Resist the urge to check your portfolio daily during volatile periods.
Building Psychological Resilience Before the Next Crash
The best time to prepare for a market crash is before it happens. Ensure your portfolio allocation genuinely reflects your risk tolerance — if a 20 per cent fall would cause you to lose sleep, you may have too much equity exposure. Maintain a cash emergency fund so you are never forced to sell investments at bad prices to cover living costs. Educate yourself about historical market cycles so you have realistic expectations. Write down your investment strategy and the reasons for it, and return to that document when volatility tempts you to deviate.
