Sparks will fly

Federal Reserve chair Janet Yellen is set to speak on Capitol Hill Wednesday morning.

And this is expected to be a tense appearance in front of the House Financial Services Committee.

In a note to clients ahead of the appearance, Greg Valliere at Potomac Research said that "sparks will fly" during Yellen's testimony.

Valliere writes: "Sparks will fly this morning as the Fed Chairman faces her House antagonist, Rep. Jeb Hensarling, Chairman of the Financial Services Committee. He believes Yellen is stonewalling on a probe of a possible leak of confidential information from a 2012 FOMC meeting."

On Tuesday, we noted that Yellen has had a rough go of getting on Congress' good side in the 18 months since she took the reins as Fed chair, with both sides of the aisle having their issues with Yellen and the Fed.

And at issue of late has been the handling of lawmaker inquiries related to a 2012 information leak, with Republican lawmakers pushing the Fed to hand over documents related to its internal probe into the issue, according the The Wall Street Journal.

Last time Yellen appeared on Capitol Hill, she fielded a number of questions related to Senator Rand Paul's (R-Ky.) bill seeking to audit the Fed.

As for monetary policy implications, Valliere says that Yellen likely, "reiterate comments from last week that a rate hike is increasingly likely this year, without tipping her hand on the exact timing."