veteran trader ted weissberg says recession talk is the problem. >> what we're seeing today perhaps as a knee-jerk reaction to the morgan stanley downgrade of growth is investors once again saying, "i can't deal with the risk, i can't deal with all the unknowns." >> reporter: today's losses extended a sell-off that began in late july, and the s&p 500 is now down close to 20% since its april high. so, are we in a bear market? >> well, maybe technically not, but it sure feels that way. >> reporter: experts say there's a battle developing in the market between investors fixated on global risk and those focused on fundamentals. and, speaking of fundamentals-- namely, earnings-- there may be trouble brewing with that previously upbeat story line. in recent weeks, companies have pre-announced weaker numbers and analysts are trimming their expectations for the third quarter. as of today, analyst forecasts call for a 15.6% jump in q-3 profits for s&p 500 firms. that's still a healthy number, but on july 1, it was a more optimistic 17%. earnings expert jharonne martis worries we'll see more ear