Global stocks slumped Thursday as China grappled with a worsening viral outbreak, leading investors to reassess the potential economic fallout world-wide. Futures linked to the Dow Jones Industrial Average edged down 0.1%, while the pan-continental Stoxx Europe 600 slipped 0.2%. The Shanghai Composite Index sank 2.8%, its biggest drop since May, on the final day of trading before the market closes for the Lunar New Year holiday period. …