Kohls Corp KSS.N added 3.1% after TD Cowen upgraded the department store operator to "outperform" from "market perform". By Shristi Achar A and Sruthi Shankar June 15 (Reuters) - Wall Street's main indexes inched higher on Thursday as megacap stocks rose on lower Treasury yields, lifting investor sentiment soured by Federal Reserve's hawkish comments on interest rate hikes this year. US/ The Fed left rates unchanged at the 5%-5.25% range on Wednesday, but indicated they could rise by at least half a percentage point this year as inflation remains stubbornly persistent and the U.S. economy stays resilient.