Behind negative returns for shares of American Express and Nike, the Dow Jones Industrial Average is slumping Thursday afternoon. The Dow DJIA, -0.13% was most recently trading 814 points (2.7%) lower, as shares of American Express AXP, +4.86% and Nike NKE, +0.21% are contributing to the index’s intraday decline. American Express’s shares are off $8.93 (6.1%) while those of Nike have dropped $6.81, or 6.0%, combining for an approximately 104-point drag on the Dow. Chevron CVX, -4.57%, Caterpillar CAT, -1.10%, and Salesforce Inc. CRM, +2.13% are also contributing significantly to the decline. A $1 move in any one of the 30 components of the Dow results in a 6.59-point swing.