Corporate insiders stocked up on shares as equities plunged in March but the mood has turned cautious. Bloomberg last week noted data from Washington Services showing executives are selling five times as much stock as they are buying, a ratio only seen twice in the last three decades.

Similar data is reported by InsiderInsights.com, which says it is near levels often seen near short-term tops. Insider selling is a fallible indicator, as executives may sell stock for any number of innocuous reasons. Still, following a near 50 per cent rally in the face of continued economic uncertainty, executives could be forgiven for thinking now is as good a time as any to take some chips off the table.