The S&P 500 fell 2.2 percent last week. That left it just 0.1 percent up for the year so far.
Earnings have been a major concern for investors. Bloomberg reports that S&P 500 profits are expected to decline 5.8 percent in the first quarter of this year and 4.2 percent and 1 percent over the next two.
Among S&P 500 members, combined quarterly profit growth has turned negative in 33 instances since 1937, data compiled by Bloomberg and S&P Dow Jones Indices show. While half of them lasted no more than six months, the others almost always dragged on, spanning five quarters on average. Out of the 17 occasions where earnings fell for at least three quarters, 14 occurred within three months of a bear market.