Yardeni on Cutting His S&P Outlook, Fed, Oil Prices

Ed Yardeni, one of the biggest stock bulls on Wall Street, talks about why he's slashing his year-end forecast for the S&P 500 Index to 7,900 from 8,400. He also says the Federal Reserve could raise interest rates two more times this year. Yardeni says Iran is likely to wreak havoc and keep oil prices elevated. He speaks on "Bloomberg Surveillance."