Direction of stock market 'really about profit margins' -CIO

STORY: Markets started September on a weak note, extending a slide that started at the end of August, as hawkish comments from Federal Reserve policymakers and data signaling U.S. economic momentum raised fears of aggressive interest rate hikes.

Nicholson said that if company profit margins "stay firm, then we could see equities accelerate higher, but if they start to compress, we're going to see equities come down and continue to be under pressure."