Overnight: The Nasdaq Composite briefly topped 4,000 for the first time since 2000 after a deal with Iran boosted investors' appetite for risk, pushing U.S

Overnight: The Nasdaq Composite briefly topped 4,000 for the first time since 2000 after a deal with Iran boosted investors' appetite for risk, pushing U.S. stocks higher. Treasury prices traded mostly higher after a strong first auction in a $96 billion trio of government debt sales this week. Gold prices closed lower as a historic agreement between Iran and six world powers to curb the Middle Eastern nation's nuclear program dulled some of the metal's investment appeal. Oil futures fell, with Brent crude briefly dipping below $110 a barrel after the U.S. & other western powers agreed to a short-term deal to curb Iran's nuclear program, fueling concerns that an easing of sanctions on the Middle Eastern nation's crude sales will soon follow & add to the world's supply. London BHP down 0.05%. Rio down 0.94%. New York BHP down 0.06%. Rio down 1.02%. LME Base metals traded lower across the complex.