US stocks slipped for a second day while investors awaited a speech by Federal Reserve Chair Janet Yellen Friday for clues on the trajectory of borrowing costs. Sentiment is turning against defensive companies in the stock market. Shares of soapmakers, utility providers and phone companies are falling out of favor and fast, marking one of the S&P 500 Index’s biggest reversals of the year. The latest to fade are consumer-staples stocks, which just slumped below the 50-day moving average monitored by chart watchers. A selloff in drugmakers Wednesday also sent health-care shares below that level. The only other industries within the benchmark that have breached deeper short-term technical thresholds? Utilities and telecom stocks. It’s an about-face for investors who spent the 10 months after last August’s market meltdown clinging to those industries’ high-dividend, low-volatility shares as bond yields plunged and the outlook for economic growth dimmed. That appetite has evaporated since the selloff that followed the U.K. secession vote, with leadership in the S&P 500 shifting to technology, financial, and industrial shares.