The tech-heavy Nasdaq 100 underperformed major benchmarks. Tesla led losses as a report of a plan to temporarily halt production at its China factory rekindled fears about demand risks. Apple touched the lowest since June last year amid the slump in big tech. But the blue-chip Dow Jones Industrial Average outperformed, with gains in stocks such as Caterpillar and Boeing. The S & P 500 traded off session lows, buoyed by gains in commodity-related stocks with oil in New York trading near $US80 a barrel. Southwest Airlines led declines in airline stocks after cancelling flights in a huge winter storm...