Market volatility — the day-to-day or month-to-month swings in the value of investments — is a normal feature of markets, not an anomaly. For investors with a long time horizon, these swings are typically smoothed out over the years, even though they can feel unsettling in the short term.
One of the more common behavioural mistakes is reacting to volatility by exiting investments during a downturn, which converts a temporary paper loss into a realised one, and often means missing the recovery that follows.
Having a clearly defined investment horizon and asset allocation, decided in advance, makes it easier to stay the course during volatile periods — the decision was already made calmly, before the volatility arrived.
It's also worth remembering that volatility affects different asset classes differently, which is one of the practical reasons diversification across asset classes matters.