why the market is down today

Why the market is down today: Stocks slumped this morning after Fed Chair Janet Yellen said there are "dangers" in current U.S. stock valuations.

"I would highlight that equity market valuations at this point generally are quite high," Yellen said. The report erased premarket momentum and raised new concerns about the markets.

Here are the top stories from the stock market today - plus stocks to watch...