This morning’s headlines of global markets tumbling on the news that Greece’s stock market and banks were to stay closed this week likely added to the panic.

For day-traders – i.e. people who jump in and out of asset classes – there is good reason to act.

But for long-term investors, notably pension investors, often the most important thing to do in times of crises is very little. This is a message seasoned investors have no doubt heard before. But it is worth repeating.

Volatility can in fact create opportunity for long-term investors. Good and bad companies get marked down as uncertainty washes across all quoted companies indiscriminately

This provides an opportunity to buy or top up holdings in good companies at better value and has a long-term beneficial impact, notes Douglas Kearney, investment director at Intelligent Pensions.

The days ahead look uncertain with a Greek exit from the eurozone – or ‘Grexit’ – a distinct possibility. This would be unchartered territory and would undoubtedly create uncertainty and market volatility.

But taking quick, rash action could hurt your portfolio, not help.