Here comes Janet Yellen ...

Federal Reserve chair Janet Yellen is expected to speak at the top of the hour about the US economic outlook.

Yellen's comments are set to be delivered before the Greater Providence Chamber of Commerce.

In a note earlier this morning, UBS' Art Cashin cautioned that Yellen could use the speech as a sort of trial balloon to see how the markets react if Yellen strikes a more "hawkish" tone, or indicates that the Fed could be quicker to raise interest rates.

The Fed has kept rates near 0% since December 2008 and hasn't raised rates since July 2006.

Ahead of the speech, stocks were mixed, with the Dow down about 45 points, the S&P 500 down about 2 points, and the Nasdaq up 3. The US dollar, meanwhile, was rallying.

We'll be back with the full speech, the most important breakouts, and any market reaction when it drops.

NOW WATCH: This simple exercise will work out every muscle in your body

Please enable Javascript to watch this video