Tech giants pay the lowest taxes among U.S. multinationals By: MarketWatch October 21, 2015 at 16:17 PM EDT The U.S. corporate tax rate is 39%, but the 100 biggest companies in the S&P 500 pay an average of just 28.4%. Read More >> Related Stocks: Alcoa Alphabet-A Alphabet-C Apple Cisco Systems Visa Whole Foods Market