Janet Yellen speaks and the market listens. Stocks trim gains as the Fed Chair says a rate hike is coming. Plus - the jobs report is on the way, but did the Verizon strike hit the numbers? And - a major US study finds cancer risk from mobile phones - should smartphones makers, and you, be concerned? Catch The Final Round at 4p ET with Rick Newman, Bobbi Rebell of Thompson Reuters, and Joe Fahmy of Zor Capital.

Winners and losers

Stocks ending the week on down note include crane maker Terex after announcing its merger with Zoom-lion was terminated, Gamestop sliding on weak profit guidance, and Palo Alto Networks dropping as higher expenses hurt current-quarter guidance.

Stocks in the green today include Ulta Salon on an upbeat sales forecast, discount retailer Big Lots as same-store sales were better than expected, and Valeant jumping on a Journal report that Japan's Takeda Pharma and TPG made a bid for Valeant a month or two ago.

Cellphone-cancer link found in rats

A major U.S. government study on rats has found a link between cellphones and cancer. It's a potentially huge development in the space, but will something like this actually decrease our massive use of mobile phones?

Looking ahead

• The big week of data kicks off on Tuesday with Personal income and outlays for April, which includes the Fed's preferred measure of inflation, the core PCE index.

• On Wednesday we'll get a read on the manufacturing sector with ISM's Manufacturing index for May.

• Finally, it's the big one, the jobs report on Friday. The Street's expecting 158,000 jobs created in May.