US stocks sink on worries about a possible hike to interest rates this year by the Federal Reserve

U.S. stocks declined as nine of 18 Federal Reserve policymakers indicated potential interest rate hikes this year, causing the S&P 500 to drop 1.1% and the Dow to swing from gains to losses. Fed Chairman Kevin Warsh hinted at ending 'forward guidance' and altering communication strategies, adding uncertainty to markets.