Dow falls 600 points with stock losses increasing after a Treasury plan to tamp down yields fails: Live updates CNBCStock futures are little changed after a steep sell-off sparked by a move back higher in Treasury yields: Live updates CNBCU.S. Stocks and Bonds Slide, Brushing Off Treasury’s Buyback Plans WSJStock market today: Dow, S&P 500, Nasdaq slide as bond relief evaporates, Walmart stock takes a hit Yahoo FinanceWall Street sinks as bond yields rise, Walmart results disappoint Reuters