Unsurprisingly, it is the energy sector which is to blame for the bulk of this weakness. With oil prices so much lower than they were a year ago, profits will be substantially lower this quarter. However, even when energy is excluded earnings are expected to decline about 3 per cent, and forecasts have still come down almost 7 per cent this year.
There are a few reasons why profits are slipping. For a start, the global economy has hit a soft patch in recent months, the US included. While it is still in generally good shape, GDP growth in the first quarter is likely to be pretty much flat. This is keeping revenue growth subdued for many corporates, while profit margins have been declining as they run out of cost-cutting opportunities.
Labour costs have been quietly increasing as the jobs market tightens, so the bright spot of the US economy has ironically started becoming problematic for Wall Street.
The US dollar has also been stronger than previous years, creating headwinds for multinationals that do business internationally.
Against the backdrop of a gloomy reporting season, it's easy to be cynical about the strength of the recent rebound.
US shares were down 10.5 per cent year-to-date at one point in February, but have rallied strongly since then, erasing all of those losses to be just a few percentage points away from their May 2015 peak. Similarly, oil has rallied 45 per cent since languishing at US$27 two months ago.
If current earnings forecasts are accurate, a tepid reporting season could be a catalyst for some of these recent gains to unwind and for markets to sell off a little. If expectations turn out to be too pessimistic, we could see a relief rally in some sectors and companies.
I'm leaning a little toward the former, but either way it will make for an interesting few weeks.
Mark Lister is head of private wealth research at Craigs Investment Partners. His disclosure statement is available free of charge under his profile on craigsip.com. This column is general in nature and should not be regarded as specific investment advice.