U.S. equity markets were halted Monday morning after the S&P 500 dropped 7 percent, as an oil price war between Saudi Arabia and Russia sent crude prices crashing. The Dow Jones Industrial Average was lower by more than 1,800 points, or 7 percent, in the opening minutes of trading while the S&P 500 and Nasdaq Composite were down 7 percent and 6.86 percent, respectively. Trading will resume following a 15-minute halt. The steep slide caused the New York Federal Reserve to increase its daily cash injections into the banking system to $150 billion from $100 billion.