Technology companies and banks led a broad rally for U.S. stocks in midday trading Tuesday following solid gains overseas. China took more steps to soften the financial blow of the virus outbreak and its main stock index rose following a plunge a day earlier. Bond prices fell, pushing yields significantly higher, in another sign that investors were willing to take on more risk. Health care stocks also made big gains. The S&P 500 index rose 54 points, or 1.7%, to 3,303. The Dow Jones Industrial Average rose 486 points, or 1.7%, to 28,886. The Nasdaq rose 181 points, or 2%, to 9,455.