MUMBAI: The decision by global ratings major Fitch to downgrade the sovereign rating of the US — for only the second time in the history of the world’s largest economy — weighed on investor sentiment around the globe which led to across-the-board selling on Dalal Street on Wednesday. Foreign portfolio investors (FPIs) were major sellers during the session, market players said.This pulled the sensex down by 677 points or 1% to 65,783 points, its first close in the sub-66k region since July 13. HDFC Bank, Reliance Industries and...