Stocks post solid gains as technology shares lead rally

Stocks shook off another bout of volatile trading and finished solidly higher Friday, led by gains in technology and healthcare companies. Despite the rally, the S&P 500 still posted its fourth straight weekly loss, extending Wall Street’s September swoon. The S&P 500 rose 1.6% after flip-flopping between small gains and losses a few times in the early going. Stocks have been erratic this month, with indexes setting new highs to start the month and then falling sharply as investors worried that values for some of technology giants had risen too high. The benchmark index ended the week with a 0.6% loss for its first four-week losing streak in more than a year. The index is now down...