Yellen speech, inflation in focus on Wall Street By: CNBC.com News May 22, 2015 at 06:06 AM EDT U.S. stock index futures indicated a slightly higher open for Friday ahead of a speech by U.S. Federal Reserve Chair Janet Yellen and consumer inflation data. Read More >> Related Stocks: Campbell Soup Deere & Co Footlocker Inc Sentinelone Inc Cl A