Wall Street’s main indexes opened lower on Monday as heavyweight technology stocks dropped on expectations of a high interest rate environment, while big banks extended gains after U.S. Treasury yields climbed to new two-year highs. The Dow Jones Industrial Average fell 56.45 points, or 0.16 percent, at the open to 36,175.21. The S&P 500 opened lower by 21.69 points, or 0.46 percent, at 4,655.34, while the Nasdaq Composite dropped 184.12 points, or 1.23 percent, to 14,751.78 at the opening bell.