US directors are snapping up stocks – should you follow?

Stock markets around the globe have been having a dreadful time. Both the FTSE 100 and the S&P 500 index have seen double-digit percentage falls since the start of August. OK, yesterday they both rallied. But with share prices moving around more in three hours yesterday than we've been used to seeing them change over three months, there's just no way of knowing how long that will last. But is this actually a great buying opportunity? One group of Americans – who probably ought to know what's what – seems to think so. Should you follow their example?