"One of the hallmarks of a bull market is that corrections are swift and shallow," notes Bespoke Investment, and "windows of opportunity" are "usually narrow".

That’s certainly been the case recently. In late January, the S&P 500 traded over two standard deviations above its 50-day average. Extremely overbought, a sell-off ensued and the index quickly fell below its 50-day average for the first time since early November.

Rebounded

Within six days, however, stocks had rebounded to “extreme” overbought levels, notes Bespoke.

This is classic bull market behaviour. As Bespoke puts it: “blink and you may miss it”.