Stocks are opening lower on Wall Street and crude prices are falling to a four-year low after the OPEC+ group of oil-producing nations said it plans to increase output.
The S&P 500 slid 0.7 percent early Monday. The benchmark index is coming off its ninth straight gain. The Dow Jones Industrial Average fell 175 points, or 0.4 percent. The Nasdaq composite gave back 0.7 percent. U.S. benchmark crude fell to $57 a barrel.
Berkshire Hathaway slumped 5 percent after legendary investor Warren Buffett announced over the weekend that he would step down as CEO by the end of the year after six decades at the helm.
This story is developing and will be updated.