A late-week appearance by Yellen could deliver fireworks.

Traders hate a late-Friday event and it seems as if they are trying to pretend that Federal Reserve Chairman Janet Yellen isn't speak or is guaranteed not to saying anything notable.

In general, Yellen doesn't like to make waves but that doesn't mean it's a layup. There are no indications she will skirt the opportunity insight on the economy or outlook for the economy. She's speaking at 3:45 pm ET (1945 GMT) at a conference titled "The New Normal for Monetary Policy."

Two things about the appearance are noteworthy.

1) It's in San Francisco, which is where she was the regional Fed President. Perhaps she'd like to make some waves in her old base?

2) Even if the speech falls flat, she is scheduled to take questions from the audience afterwards and could drop some hints about the economy then.

Janet Yellen

The market will be looking for hints about when rates will go up. It's extremely unlikely Yellen will signal anything specific but the market will look between the lines. There's also the risk that her statements are misinterpreted in a thin market late in the day.

In general, the trade on Yellen forever has been to bet on her being a dove. Even with the removal of 'patient' in the FOMC statement, it still paid to make a dovish bet as the dollar fell hard.