But they should think twice. Shares have probably already suffered the worst of their falls. Those who decide to sell blindly now risk locking in their losses at the worst point.
This does not mean investors should be "buying the dips" as US investors have done so blithely. However, they can opt for quality - solid, ungeared companies relatively immune to a general slowdown or the threat of higher interest rates. Here are five to watch.
First is British Telecom (796p). Highly-rated telecoms stocks have come crashing down, but BT is built on solid foundations. Its alliance with AT&T will allow it to capitalise on growing demand for telecoms services, while its balance sheet, awaiting a $7bn (pounds 4.2bn) cash injection, is robust.
The same goes for Glaxo Wellcome (1753p). Demand for the drugs giant's products depends on its pipeline rather than economic spending. And there is always the prospect of a cost-saving mega-merger.
Food retailers are the other defensive stocks, as consumers are more likely to spend less in the pub or boutique before cutting back on supermarket shopping. The two groups with the best records in the past decade - Tesco (173p) and Marks & Spencer (541p) - look worthy of any investor's money.
Finally, for a stock as close a proxy to cash as you will find in the UK, look at Associated British Foods (507p). Sir Garry Weston's group pays healthy dividends and is sitting on a huge cash pile. With values falling all around him, Sir Garry might also be able to snap up a few bargains.