Morning Bid: Wall Street gets vertigo

By Mike Dolan -What matters in U.S. and global markets today By Mike Dolan, Editor-At-Large, Finance and Markets A rare shakeout in Big Tech and chip stocks on Tuesday rippled around world bourses overnight. The fact that it came with few triggers other than growing unease at sky-high valuations left investors wondering if a more prolonged pullback is in store. The backdrop to Wall Street's worst day in almost a month, which saw both the S&P500 and Nasdaq shed more than 1%, was a surprisingly positive ...