Global equities tumbled Tuesday as concerns of inflated valuations and an uncertain macro environment grips investors ahead of Nvidia earnings this week.  The pan-European Stoxx 600 opened in negative territory on Tuesday with mining-linked stocks and banks leading Europe's losses. The Stoxx Europe 600 Technology Index shed 1.4%, following in the footsteps of U.S. stocks as fears of an artificial intelligence-fueled bubble persist.  The three major U.S. indexes, Dow Jones Industrial Average, the S&P 500 and ...